Developer Rovio has denied handing over user information to UK and US officials, suggesting that any leaked data is coming from third-party ad networks, not itself.
"Rovio Entertainment Ltd, which is headquartered in Finland, does not share data, collaborate or collude with any government spy agencies such as NSA or GCHQ anywhere in the world," the company said in a statement.
Rovio's denial comes after The New York Times, citing data provided by Edward Snowden, reported that the National Security Agency and British intelligence teamed up to collect and store user data generated by "dozens of smartphone apps," including popular games like Angry Birds.
Since 2007, "the agencies have traded recipes for grabbing location and planning data when a target uses Google Maps, and for vacuuming up address books, buddy lists, phone logs, and the geographic data embedded in photos when someone sends a post to the mobile versions of Facebook, Flickr, LinkedIn, Twitter, and other services," the Times reported.
According to Rovio, "the alleged surveillance may be conducted through third-party advertising networks used by millions of commercial websites and mobile applications across all industries."
If that's the case, "it would appear that no Internet-enabled device that visits ad-enabled websites or uses ad-enabled applications is immune to such surveillance," the company continued. "Rovio does not allow any third party network to use or hand over personal end-user data from Rovio's apps."
Mikael Hed, the CEO of Rovio Entertainment, said Rovio might have to re-evaluate working with third-party networks if they are being used for spying.
"Our fans' trust is the most important thing for us and we take privacy extremely seriously. We do not collaborate, collude, or share data with spy agencies anywhere in the world," Hed said.
The news comes as the Department of Justice announced that tech firms will be allowed to release more data about government requests for information. Previously, they had to lump national security-related requests in with ordinary law enforcement requests, but they can now break them out, in bands of 250.
Apple has already revised its data, revealing that it received between zero and 249 national security orders between 1 Jan and 30 June 2013.