This is fun, I have a tablet here on my desk I was given to repair a couple days ago. It's a mainstream tablet here in greece, sold for 70-90€, the sort of thing you'd buy if you are an "ordinary user" who doesn't know any better.
Well it's running a 4.x android with a custom marketplace and it is FULL OF ADWARE. Seriously. There's fullscreen porn popup ads on the OS itself. There's hundreds of spam notifications, a "fake" screenlocker which captures your taps into ads, etc, etc. Seriously, this thing is like a Windows XP SP0 PC from 2005 after heavy adblockless porn usage with flash and java on. I actually haven't seen anything like that this decade.
This is what you get if you buy an off-the-shelf tablet or phone here. This is what "ordinary users" get. We gave up control of our own devices in the name of security, yet shit like this can still happen.
(Sorry for the OT rant. Seeing that tablet pissed me off.)