"I found some proxies that would change and/or hide your IP address." You must be mistaken, all proxies, not some, are supposed to hide your IP address. You can use Hide My IP or Hotspot Shield, they are both what I use a lot.
I don't understand what you mean by being 'found' or 'banned', all hackers will be banned. Doesn't matter if they use a proxy, they can still get banned?.... Weird question... I didn't understand it, at all.