Do you have a clue how many accounts get hacked on a daily base?
Just take a look at some hackers forum, section > account dump...
It is your responsibility to keep your passwords safe, not theirs.
But you actually never read their T.O.S. ?


5. Rejection/Termination.
FileServe may reject your Application and/or terminate your Membership at any time and for any reason, in our sole discretion. Such reasons may include, without limitation: (a) where FileServe believes that you are in any way in breach of the Agreement; and (b) where FileServe believes that you are, at any time, conducting any unauthorized commercial activity by and through your Membership.
Most of the time, accounts get banned only because of misuse (being used for downloading from multiple places at a time)