Topic Forum Ignore now works account-wide.
For instance, this thread:
OP was put on ignore, and surprise!
Suup Bonkerz, lord of rapping mattybee eh :D
Edited by Spelz on 4/1/11 7:33 AM (PDT)
Thank you August for sharing this delightful discovery.
This artful technique has already revealed to me the true identity of lolwut, the author of Shout our to <Evil League of Evil> - http://us.battle.net/wow/en/forum/topic/2325093062
My hope is that Blizzard implemented by design and not by accident.
Edit: I can't format links.
Apparently, this is working as intended.