Mark, there are a bunch of people leading efforts so it’s a little disjointed. One place that tends to have most of the information (but not all) is the Performance Marketing Alliance. http://www.performancemarketingalliance.com/

Where you can get the most up to the minute info the minute it happens is on Twitter by searching for #advertisingtax.

I see some independent people going after them, but having 1 central source for people to come together would be great. If amazon is dropping affiliates from the state, combined with thousands of other affiliates and merchants from the state threatening the same, I think it’s powerful enough to end the ridiculous attempt to unconstitutionally tax.