Another day, another lawsuit. A class-action lawsuit filed last week in California state court is accusing “Angry Birds” of violating users’ privacy. The lawsuit is directed against Apple for allowing “Angry Birds” to collect user information, reports “Westlaw Insider” (http://macte.ch/jxAbI).

Specifically, the lawsuit alleges that Apple doesn’t screen apps available in its App Store to prevent them from obtaining private user data. Plaintiffs’ allege that their data is being collected through the app Angry Birds. According to the complaint, a majority of popular apps on Apple’s App Store collect user information without the users’ knowledge or consent, says “Westlaw Insider.”

The apps collect information about a user’s gender, age, location (via GPS), which apps he or she uses and for how long, and to what extent he or she uses the app. The tracking is possible because Apple assigns a UDID (Unique Device Identifier) to each iPhone, iPod touch and iPad, and apps can access that number. Advertising companies figured out this number can be used for tracking, much like a cookie in a browser.

If an app passes that number along to an advertiser, the advertising company can use it to build up a profile of the user, as well as keep track of which ads it has shown to a user before and which of those ads the user clicked on. Unlike browser cookies that you can block or delete, you can’t do this with apps that use the UDID, because the ID number can’t be changed.

The suit cites a” Wall Street Journal” article from December 2010 that says developers can combine the UDID with other personal information found on the device including user name and password, contacts, current location, and in some cases the phone owner’s name. It also cites a study by the director of information security and networking at Bucknell University, which found that many applications collect the UDID number and user login data that ties to a user account.

While these tracking companies claim that the information is aggregated and not linked to an individual, there is nothing stopping such activity, according to the recent lawsuit. Two similar lawsuits were filed last December in a federal court in Northern California and San Jose, California. . Both claim iPhones and iPads are encoded with identifying devices that allow advertising networks to track what applications users download, how frequently they’re used and for how long. The transmission of such data violates computer-fraud and privacy laws, per the suit.

A second lawsuit is against AT&T and claims that AT&T has “systematically” overcharged iPhone and iPad owners with capped data plans by inflating the amount of data they download and adding “phantom traffic.” The complaint, filed by Patrick Hendricks in federal court in California, claims that a “significant portion” of AT&T’s $1.1 billion of wireless revenue gains in the last quarter came from the bogus charges and overbilling, says “Computerworld” (http://macte.ch/sqijk).

Hendricks’ lawyers asked a judge to grant the lawsuit class-action status; if that happens, the case would be open to millions of iPhone and iPad owners in the U.S. Citing evidence obtained by a consulting firm hired by Henricks’ attorneys, the lawsuit contends that AT&T regularly overstates incoming data by 7% to 14%, and in some cases by as much as 300%.

“AT&T’s billing system for iPhone and iPad data transactions is like a rigged gas pump that charges for a full gallon when it pumps only nine-tenths of a gallon into your car’s tank,” the complaint states.

“Computerworld” says Hendricks’ suit also alleges that AT&T bills for data transfers that never took place. During a 10-day stretch, the same consulting firm found that AT&T billed a new iPhone’s account for approximately 2.2MB of data transfers, even though the smartphone had had all push notification and location services disabled, no e-mail account configured, and no active apps, the article adds.

— Dennis Sellers