Riot will put files on your computer once you are banned. You need to make sure to clean up these files before you play on other accounts, or you are at risk of being banned again. We recommend you use Revo Uninstaller to remove and clean up LoL, then reinstall it. Or just format your pc.
Nope, the bans are either botted accounts/new accounts or been obvious in the past and got a ban. Also not to mention any usage of a script in the past as well.