Apple, Motorola, and three major wireless carriers are the latest to face a class-action lawsuit over a smartphone privacy scandal, with Carrier IQ, HTC, and Samsung also facing allegations that they spy on users with software installed on smartphones. While Carrier IQ makes the software, it is installed on phones manufactured by hardware companies and sold by carriers, providing plenty of targets for lawsuits.

We noted the existence of two class-action lawsuits targeting Carrier IQ, HTC, and Samsung last week. Another was filed in US District Court in Delaware Friday against a bigger roster including Carrier IQ, AT&T, Sprint Nextel, T-Mobile USA, HTC, Apple, Samsung, and Motorola Mobility. Filed on behalf of four plaintiffs who are iPhone, HTC, and Samsung phone users and also customers of AT&T, Sprint and T-Mobile, the suit notes that "defendants Samsung, Apple, Motorola, and HTC pre-install Carrier IQ software on cell phones used by its customers on the AT&T, T-Mobile and Sprint networks."

Carrier IQ and its customers say the software only collects diagnostic information to help them improve service, but the lawsuit says that "[i]n addition to collecting device and service-related data, Carrier IQ’s software can collect data about a user’s location, application use, Web browsing habits, videos watched, texts read and even the keys they press." The suit claims violations of the Federal Wiretap Act, Stored Electronic Communications Act, and the Computer Fraud and Abuse Act, while demanding monetary compensation as well as a permanent order preventing the defendants "from installing software on cell phones that could track the users’ information in violation of federal law."

Whether the charges can be proven is unclear. Customers must assent to smartphone privacy agreements that typically allow some sort of data collection, and some security researchers have disputed the claim that Carrier IQ software collects more than is lawful. Carrier IQ has denied any invasion of users' privacy, while Apple told Ars last week that it used Carrier IQ to record diagnostic information anonymously, and "did not record keystrokes, messages or any personal information for the diagnostic data." AT&T and Sprint have also told us their use of Carrier IQ software is aimed at gathering information to improve device and network performance, and that they do not collect personal information, like text messages or photos.