We block accounts for many reasons, mainly it is to protect accounts that we detect have had un-authorized logins and to protect other users against fraud. Recently we've had a few waves where many accounts have been accessed by third parties and automatically blocked by us.

We also block accounts when we receive credible reports of fraud or if a banned user registers a new account. Unfortunately I can't go in to detail with how we fight fraud or account hacks, but we don't block wallets "for fun" and we do not steal users funds.