Its forums similar to this that cause your email address to one day get leaked.
If you use one email (and not a seperate one for wow) then potential scammers will send you emails from @Blizzard @battle.net (Easy to do that) - I have had same email since starting in 05 so get a lot of this spam/scam shit daily.
pretending to be them saying someone has tried to hack you, and asking for all your details. or to click a link.
they will then of course retrieve your account.
Blizzard wont email you sayin "YO BRUV SUM1 HAKIN U M8 NPZ WE PRO N GOT FIREWALLZZZZ111111"
Point is:
Dont do anything them emails say son!