In late November, Twitter started contributing its DMCA takedown letters to Chilling Effects, the online clearinghouse jointly organized by the Electronic Frontier Foundation and many universities and law schools.

Chilling Effects says it received records of 11,500 total takedown notices in 2010, as of Dec. 15. Major contributors include Google, Yahoo and Digg.

Techdirt’s Mike Masnick flagged the Twitter takedowns, noting that many of them are for tweets that contain links to copyrighted material. Why go to Twitter and not the content host itself? he asks.

Chilling Effects founder Wendy Seltzer said she believes Twitter has been getting the takedown notices for a while but only recently started submitting them for public posting.

Using Twitter to get out the word about content may well be a growing phenomenon. In August, BitTorrent released a tool for more easily tweeting about torrent files. A friend of mine who’s an avid Green Bay Packers fan recently told me about a Twitter account he follows to find streams of football games he doesn’t have access to on TV.

“It’s interesting that they are receiving takedowns, given that most of what they’re hosting is little 140-character bursts of expression,” Seltzer said on a phone call yesterday. “Copyright holders are pushing the complaint out further, not going after the user who hosted, or even the user who pointed, but going after Twitter because it’s made itself a central location for the collection of information.”

Seltzer said that under the U.S. Supreme Court Grokster ruling, it’s possible that users could end up on the wrong side of the law for inducing infringement by posting a link with the intent to encourage their Twitter followers to access or download infringing material. But as long as Twitter complies with takedown requests, it should be within the safe harbor rules of the DMCA, which protect providers of information tools, said Seltzer. “Twitter doesn’t have an intent to infringe, so they would have a solid argument.”

A spokesperson for Twitter declined to comment, citing mellowness in the office over the holidays.

What’s different is that rather than playing in their own siloed version of the game, friends can place businesses in each other’s cities, and benefit from the success of these franchises. CityVille also uses 3-D rendered buildings and characters and will be released in five languages, both things Zynga has never done before.

But for all those firsts, the game will only be released on Facebook. Zynga is of course working to diversify its platforms, adding iPhone, iPad, Android and Yahoo. But as a matter of priorities, said CityVille general manager Sean Kelly, “We feel like Facebook is the best partner to prove out.”

Kelly, who previously was GM of Zynga’s FishVille, declined to say how long Zynga had been developing CityVille, or how many people were on his team. However, he said this was the “first job ever” for half of his developers, and that his team also included game industry veterans from places like Blizzard, as well as longer-term employees of Zynga. Plus, one CityVille product manager came from Harvard Business School, so he helped the team create its in-game franchising arrangements. And an architect advised on how to properly build structures within the game.

This is only Zynga’s third game launch this year, after Treasure Isle and FrontierVille. The actual release of CityVille will be sometime over the next few days Update: weeks, based on the alignment of the stars and other factors.

To clear things up, I’ve put together a basic Twitter guide that explains how to use it, Twitter lingo, privacy options, mobile applications that can be used with the service and problems that it has. Let’s get started.

Twitter limits social-networking updates to 140 characters or less. The service is surprisingly useful, but leaves room for improvement.

What is it? In short, Twitter is a free social-networking tool that keeps people connected with one another and with sources of information. Twitter users submit updates about whatever they’re currently doing, and these updates cannot exceed 140 text-based characters.

Lingo: Twitter is the name of the service. The term twittering describes the activity of updating a Twitter account. A tweet is an individual Twitter update. Twitterers are people who use the service.

Followers, not Friends: Social-networking sites like Facebook and MySpace use the term “friend” to refer to people who are connected with one another, but Twitterers can simply follow one another’s messages by finding a person’s username and selecting a “Follow” option. This alerts the person that you’re following them, and they can reciprocally choose to follow you, or not.

Why use it? While some people primarily use Twitter to post updates about their activities or comments on the news, I use the service more as a follower, allowing me to see quick snippets of news as it occurs. Most tweets are written by real people, while others, such as updates from news organizations that you’ve selected, are automatically generated. Many tweets include the addresses of Web sites with relevant articles that tell readers more on a topic.

Where is it? Twitter works on your Web browser at Twitter.com, where user updates appear in a simple list form as they are submitted. After you’ve signed up and started following other people, those people’s updates, or tweets, will appear when you log onto Twitter.com using a username and password.

Twitter also works on mobile phones, where the 140-character limit allows messages to be sent and received via SMS text messaging. Tweets can also be sent and received via email. Users with smartphones like BlackBerrys or iPhones can use one of the many popular mobile applications for accessing Twitter, which offer much richer options than simple SMS does; I’ll get into these later.

Privacy: Unlike other social-networking sites such as Facebook, Twitter isn’t focused on holding and sharing personal information about its members. Indeed, the service operates with a majority (80%, according to the company) of users opting to keep their updates public, that is, follow-able by anyone, without permission. This openness encourages people to follow one another or to see who others are already following, and then follow the same people.

However, users can opt to protect their updates, meaning they must grant permission for others to follow them. If you’d like to sign up for Twitter, but aren’t comfortable putting your first and/or last name on the site, you don’t have to; instead, just tell others your username.

Twitter Page Personalization: Each user has a Twitter page showing all of his or her updates, or tweets. (Mine is twitter.com/kabster728, and you can follow me.) This page also shows the number of people a user follows, how many people follow her and how many total updates she has posted.

Twitterers can customize their Twitter page by uploading a photo to be used as the background. The icon representing each user can also be personalized, and this is important because it appears beside that person’s tweets on Twitter.com, where followers recognize and appreciate its familiarity. Some people, including me, use pictures of themselves as their icons, while others use random shots.

Apps/Clients: Twitter works on any browser, and will also work on a mobile browser. If you have a mobile device like the BlackBerry or iPhone, you can jazz up the experience by downloading a third-party app like TwitterFon, TwitterBerry, Tweetie or Twitteriffic. Twittervision, another mobile app, plots points on maps to show where tweets originated. Desktop clients also abound, including Twhirl and TweetDeck. Twitterfeed will set your blog to automatically post content to Twitter.

@Replies, Direct Messages: Each tweet that appears in your Twitter feed can be replied to using a shortcut arrow that appears beside the tweet, and these responses to tweets are called @Replies. So if JoeSchmo tweets to say he saw the new James Bond movie and hated it, you can reply to this with a tweet of your own that says, “@JoeSchmo I still adore Daniel Craig.” These @Replies appear for everyone to see, and must start with @ plus the username of whomever you’re responding to.

Direct Messages differ from @Replies because they can be sent only between people who are following one another. These messages aren’t posted publicly. They appear on your Twitter.com page in a right-side section labeled Direct Messages and will also be sent to your mobile device if you have one registered with Twitter.

Favorites: If you read a tweet that you really like, you can save it as a favorite by selecting a small star beside the tweet, thus adding it to a Favorites section on your homepage. Anyone can see anyone else’s Favorites, regardless of whether or not they’re following one another.

Problems: Twitter’s bare-bones approach gets to the point quickly, displaying tweets in a simple, quick-read format. But the site is lacking in many areas. It used to enable searching for people on Twitter, but that capability is currently down. Now, to search for friends on Twitter, you must upload your email contacts from a Web-based mail service. The company says it plans to have people-search working again by the end of the year. Meanwhile, search.twitter.com enables keyword or location searches.

Twitter lacks the ability to sort tweets according to what the user wants. If I just want to see tweets from real people and not those that are automatically generated, I’m out of luck. Same goes if I want to keep certain friends’ tweets in a prominent place on my homepage; Twitter has no way of doing this.

Twitter users aren’t notified when someone responds to their tweet with an @Reply. I recently happened to look at @Replies on my Twitter homepage and found three from people who follow me (I don’t follow them).

If you’re adding a Web address to a tweet and the characters in the URL take up too much space, Twitter will automatically use TinyURL behind the scenes to shrink your long link into a shorter one when you post your tweet. But this works only if you have enough remaining characters in your tweet to fit the long version of your link. A built-in TinyURL converter on the page would help immensely.

Twitter says it’s working to make @Replies more effective. It also says it plans to do more with filtering and sorting, so that the Twitter interface is more useful. In the meantime, Twitter does a good job of giving people simplified news about others and the world around them. If you’re often in a rush, Twitter can be a great resource for fast information.

Edited by Walter S. Mossberg

• Email us at mossbergsolution@wsj.com. Find this and other columns and videos online free at the All Things Digital Web site: http://walt.allthingsd.com