Unless you're running Graphene or a similar security minded distro the sandboxing isn't very good. Okay let's be honest it's fairly abysmal at preventing fingerprinting. It could almost be accused of not even bothering to try.

But one example: https://news.ycombinator.com/item?id=43518866

The mobile operating system developed by the enormous ad tech company doesn't try to prevent fingerprinting?! :O