Yes, it's enough for them to make out a fake check and then cash it... happened to someone I know - someone had gotten ahold of their bank account number, routing number, bank name and address and made up a fake check. The signature line had printed on it "No Signature Needed".... Happened twice, about 2 weeks apart, for the same amount (like $103.25 or something like that). Didn't even need the signature of the person whose account it was for the bank to cash the check and even let it clear. Needless to say, their account has since been closed as a result (closed it to prevent it from happening again).
JW