i think niantic check every account in database for ...

[sumfool]

i think niantic check every account in database no matter how old (so every account from the day the game opened or even earlier maybe into alpha) for impossible feats such as all the achievements at once for example or all the levels at once .
i think if your account has ever done this no matter how old . it will be banned it is a matter of time .
i realized maybe this is whats going on when my ancient account which i have no botted on in forever just took a ban .

 

[sumfool]

anyone have anything to add to this theory ?

 

[imballsdeep]

anyone have anything to add to this theory ?

I agree.