This question already has an answer here:
It seems so easy to pirate apps for Android it's as if no one even cares. It's as easy as google searching for the apk and then installing it. Isn't this surprising as some apps cost money?
Wouldn't it be easy for Google to stop piracy as the Google Play Store knows which apps are installed and it would raise a red flag if an app that cost money is installed but there was no history of it being downloaded through the app store?
Am I missing something? Is there a technical detail that makes it harder than I think to know if someone has pirated?
I'm not saying it's good, but consider how now many ISPs basically have an automated process to scrape IP addressees from a bit torrent tracker hosting some of their copyrighted work, and send them an official looking letter threatening law suits if they don't voluntarily pay them money. I'm a bit surprised no Android Apps are doing this, especially considering almost all apps connect to the internet and get the information of the device. Come to think of it, if an app is detected as pirated could the company call the phone and ask how you purchased the app and use it against you in court? I guess the thing is many people do this.
UPDATE: for example Pokemon Go can be downloaded for free in countries that aren't supposed to have it. It's as simple as google searching the download, so it's as if they aren't even trying to prevent piracy.