FReepers here at FR noted the bomber was making a smiley face on a map with the locations of the blown mailboxes.
These FReepers gave him the name Smiley Face Bomber and notified the FIBs who later made the arrest.
*Smiley Face Bomber is searchable.
Thanks for that bit of History, Smith!
I'm sure the FIBs will properly punish those FReepers for their Good Deed, and probably all the rest of us as well.