600 NL, Deep Stacks and Crazy Action

[9cao]

Table is 5-handed and I have been at this table since it has opened (about 25 minutes). The action is absoluetly insane with one player driving most of it. He has taken down a $1400 pot with 73o, which he called a huge preflop raise and put one guy on tilt. His standard preflop raise is usually between $60-$100 (blinds are $3-$6) and is raising a majority of hands. The other players have been willing to call these raises pretty frequently (even multi-way) and because of this, the stacks are deep. I have played only one hand really where I doubled with AA.

The idiot just lost a huge hand when this came up.

SB - ($800)
BB - ($2200)
Idiot - ($500)
CO - ($1600)
Hero - ($1200)

Hero is dealt black nines on the button. The idiot opens for $100 and it is folded to me. What is my action?