I've looked up some users in this site and it said "This user is banned" or something similar to that. How do users get banned? Is it because they are rude?
Yes, it is always because of rudeness.
Rudeness can take slightly different forms though.
Oh...thanks for the heads up.
If users are banned, can't they make new account and be rude all over again?
The logical answer would be yes...if they honestly cared to even go to that much trouble