Well better to a MLP:FIM forum instead of something that would cause this:
http://www.youtube.com/watch?v=_SsUTLAhbWE

Woah, all the quotes are broken!
Ok, now it redirects to Steam...

I think it would have made more sense to leave IronStar's ones until the other ones were gone...

Greatly appreciate it, good sir.

That's hilarious.

Love how she says "Oh NO Jackie. I can't" and then keeps watching, LOL. My grandma would have done exactly the same thing :)

Actually, it was these guys. I'm currently at UAM and they used to drill this into our heads every day ;p

Awh, I think I missed all the fun D:

fighting to prevent a brony from redirecting everyone to some trash forum is not fun

There's still plenty of fun on page 2 and onward.

Fun/ Potentially one of the most dangerous bugs on the net.

Hmm, seems GOG forums got exploited. Are there still possible redirects? Should I disable javascipt or has it been fixed already?

Multiplying, badly escaped ampersands:
http://www.gog.com/en/forum/general/im_hoping_this_will_not_hurt_script_languagetextjavascriptalertsorryscript
http://www.gog.com/en/forum/general/yes_title_im_a_bstard

Also the bold html tags on some newsposts:
http://www.gog.com/en/forum/general/release_blitzkrieg_anthology
http://www.gog.com/en/forum/general/release_torchlight

So, some of their script was probably relying on the insecure behavior to format thread titles... awkward.

EDIT: I guess it's equally possible that they are just doing sanitation at the wrong place (after their script does formatting to the titles... they just forgot to do sanitation during the formatting phase).