haha, I was watching that too. I haven't seen one, but I think it says on the Mass Wildlife site or the regulation book ( could have been NY, I have a license there this year also) that if you catch one, you're supposed to kill it. Things looked nasty...
Found this when i googled snakeheads in mass.
http://docs.google.com/viewer?a=v&q=cache:LyVj1l1RxpcJ:www.mass.gov/dcr/watersupply/lakepond/downloads/rrp/snakehead.pdf+snakeheads+in+massachusetts&hl=en&gl=us&pid=bl&srcid=ADGEESgnKR8sPyybl12jn0807dcOkS9zuGPv4yR9-D-qQxHGhtow5B-W-aYm7gMICipkr0Vkd_Z8_VJtEJTJmbrI6laVuc9wSk45Zv8CaEAHiI23PYhx2ICj7JJh9JacHEtfLLGsBvei&sig=AHIEtbS-JK3OQD_QCaTME6Vg3zS4qSudAg