Thousands of smartphone applications available for download from Google's Play Store may be collecting too much data from users, a security firm has said.
According to the security firm Bit9, about one-quarter of over 400,000 apps studied are "suspicious" or "questionable" because of what they do in the background, such as location tracking, accessing contact lists or harvesting the contents of email messages.
Bit9 chief technology officer Harry Sverdlove wrote in an email interview that some of the most aggressive apps are programmes purporting to be affiliated with popular brands, such as Facebook and Zynga.
He said that wile the extra functions don't necessarily make the programmes malicious, they do raise questions about the developers' intentions, The Sydney Morning Herald reports.
"Including a common app or publisher in the title is not a guaranteed sign of suspicious behaviour, but it is certainly a technique that malicious authors use to trick users into installing their apps," Sverdlove wrote.
According to the paper, Android phones warn users when they download applications about what information the programmes will access.
Whether most people actually read those warnings is another matter, it added.