For instance a keyboard like this would not be allowed in a mlg tourney?
http://www.amazon.com/Razer-Blackwidow-Ultimate-Mechanical-RZ03-00381900-R3U1/dp/B008U5ZNIG/ref=zg_tr_402051011_29
Also, can you get banned if they catch you using the side keys? I know they can somehow find out if you're using macro keys to do multiple actions at once.

No they are not illegal why would they be?

You are allowed to use that keyboard + razer naga if you want to at a tourney

Macros are like one of the biggest things in wow, why would you not be aloud to use them

It should be fine if they are set to in game macros or abilities. The issue would be if you used the macro programs that come with the keyboard to record keystrokes and set those on the M keys. But even then I don't know that it is illegal considering they allow multiboxing. As long as there is user interaction they don't seem to care.

bro, these keyboards are illegal...

a joint effort of the FBI, Blizzard, and homeland security have come together to bust kids macroing.
I think the penalty is 5 years in federal pound you in the ass prison and up to a 200,000dollar fine.