If the game manipulates cookies only, then all the other methods of tracking users are already immune. And many of the more "sophisticated" marketers have long ago adopted these methods in addition to or instead of standard cookies.

I still think this game is a charming idea.

There are a few different ways; Flash Shared Objects (https://en.wikipedia.org/wiki/Local_shared_object ), using Browser + Machine ID information to make sure cookies are linked to the right machine, etc... - see http://samy.pl/evercookie/ for a few different other methods

So the idea of the program would be, with enough mis-information it starts working for everyone not just users of the program. (Else there's little point to it)

So really it's not about the users it's about stopping them destroying your current accurate data.

So all you need to do is identify if a user is a malicious one and ignore them.

So how does one identify dodgy data? Benford's Law is one example.

Of course this can be fought, but then you fight back and the war begins.