Glad you asked!
Users get banned for wrong doings, such as using a duplicate accont or constantly voting stuff down. You might wonder, 'How do you keep them from the site? There are hackers around!'. We ban user using a code unique to every internet-connected device called an IP adress. Every computer, iPhone, etc. have an IP Addreess, and what we do is block the IP the accont uses. If the banned person tries to make another accont, the IP ban will block it. We also apply temporary bans for user who simply need a warning; or do not deseve a premantant ban yet.
This will show you the users who have recently been banned, and the one who already are. Mods update this each time someone is banned. There are more users banned than what is shown below, due to various reasons. > http://Pokemondb.net/pokebase/meta/16065/why-were-you-banned-for-moderator-use
This will show you who is under threat for a ban. This is where anyone can casually report someone of breaking a major rule. Do not report unless the suspition is very high and you have evidence. >
This will show you the things you can get banned for, and why. >
Basically, you can stay off the ban list by following the Rules and staying out of trouble. Once you have read the above pages, you're good to go. The rules and getting banned are not ment to make you worry; just to keep the site secure from wrong-doers. The site has been the 'DramaBase' as times, and we do our best to keep that in the past.
So generally you get banned for being a brat to others, or breaking easy-to-follow rules.
Hope this was helpful to you ;)