In that case it appears he took action as soon as the Weiner agents informed him of the find.
Her is hoping they find more as they search. Like another server or backup site
I think there is tons of undiscovered evidence out there. I read a post on FR that suggested NY child services investigation into Weiner is involved, may have trigged the FBI to act, as NY child protective unit came into possession of evidence that includes (irrelevant to child protection) evidence that plays in the illegal server investigation.