This could be the reason your phone's battery is on death's door half the time.
Almost 15% of all smartphone apps could be loading invisible ads to artificially inflate user numbers, which could potentially eat as much as two gigabytes of data per day on images and videos that the users is unaware of.
The study, which was released on Thursday by fraud detection firm Forensiq, showed that these apps can launch a number of battery intensive operations in the phone's background which continue to run even after you exit the app.
Having taken in the data from 12 million phones, and 16 billion adverts, Forensiq found that over 13% of ads on Android, Apple, and Windows mobile devices were hidden in this manner.
The company's chief scientist, Mike Andrews, told Mashable that they "wanted to show the public how blatant and obvious and hurtful all this fraud is — not just to advertisers who pay for ads that no one sees but also people using these apps on these tiny devices that are bandwidth-limited and power-limited".
Thankfully users can take some simple steps to protect themselves against these issues. You can scan the app review sections for of excessive data or power usage, thus showcasing the apps that are up to these tricks. Alternatively, you can switch off access to data for apps that don't need constantly.
Forensiq have said the problem appears more commonly in apps created by lesser-known publishers, and that the more popular apps tend to be less prone to these issues, so maybe it's time to have a root around you phone and get rid of some of those apps that are cluttering you memory, namely those games you downloaded, played once, and never deleted.