What if 'you' are an anonymous remailer service account and a bitcoin address? It would be amusing if patent trolling got bad enough to force startups to operate on the black market.
After all, what's the ROI on legitimacy if the state can't protect you from banditry?
<sociopath>Other patent assertion entities would be inspired to think carefully about targeting entities subscribing to our protection service.</sociopath>
I dunno how it is in US, but in other places all kinds of shady businesses are protected by organized crime. Try to harass their businesses and jokes may end pretty quick.
I'm late to the thread here, but, as one who has received a threat (entirely different situation), non-specific threats by themselves are usually non-actionable.
They would make sure you're behind bars in no time.