where to report US und-eraged stuff online?

some fucker signed up with und-eraged stuff and not sevent-een. I know one site down wont make a difference but one down is one down.

His host has the same nameserver as the site, 2 lines text and hasnt been changed since 97 so thats prolly the only site he hosts. Tampa FL PO Box and some email adresses. Im used to german fif-teen yo shit but this ruined my mornin capp and its American, the fucker even has a US compliant line on the hosting site. No abuse addy obviously.

So where do I report this, already told ccbill to cancel his account, they will.

Thanks

EDIT : the sites in Colorado

City: PARKER
State: Colorado
Zip code: 8013X
Country: United States