just yesterday my account was working fine, today i saw it says "your account is invalid".

i received no warnings, no explanations, no reasons.
if there is a problem with my account, at least tell me what the problem is, so i can prevent from making the same mistake in future.

my username was: dickwall
if it is possible, please restore my account.

just keep in mind that by suddenly removing accounts you're establishing a dangerous precedent.