You can report hackers by sending an e-mail to firstname.lastname@example.org . Please include the following:
# Your account name/realm.
# The hackers account name/realm.
# A brief description of what happened.
# Any evidence you may have.(Replays, Screenshots)
(You may also report a hack, by sending an e-mail to hacks@Blizzard.com , with the same information.)
But I recommend using the webform located below to report either, as it is very simple to use.