Excellent principled stand by Mikko.

Minor problem ".... In fact, I'm not expecting other conference speakers to cancel. Most of your speakers are american anyway – why would they care about surveillance that’s not targeted at them but at non-americans."

Incorrect - NSA surveillance most definitely HAS targeted Americans in America. That is precisely what the Snowden disclosures show - leaving aside all the contortions of "Only Collecting data is not surveillance - Metadata is not Surveillance, etc, etc"