US federal prosecutors have opened an investigation into private data handling practices of a number of mobile applications on he iOS and Android platforms.
The Wall Street Journal reported that the prosecutors are examining whether the applications illegally acquired and transmitted user's private data without asking permission.
Popular US-based online radio service Pandora said on Monday that the firm had received a federal grand jury subpoena relating to the behavior of the firm's mobile applications.
Like many application developers, the firm shares limited data with third parties in order to deliver 'targeted' advertising.
It's not known if the investigation relates specifically to this type of information sharing. If it does then Pandora is just one of a vast array of applications which similarly using third-party advertising services.
However the Journal quoted iPhone developer Anthony Campiti, recipient of a similar subpoena, who said the federal action amounted to "information-gathering to get a better understanding."