Only problem: you actually have to care enough about an issue to risk getting arrested. I'd be surprised if anyone cared that much about Apple's patent trolling.
On a large scale, make something disruptively innovative to fight back.
#BoycottApple may work by alarming and reminding Apple of their unethical act (to the crowd). But the effect is small because it has nothing to do with Apple's product quality and customer service. If no one buys Apple products any more, we won't necessarily be better off.
That said, I think Apple seriously doesn't have to go this far. If they have the energy to continue innovating there shouldn't be any fear.
What we're trying to fix is that companies can even get injunctions for stupid reasons, and that patents are used as warfare rather than for encouraging innovation. Boycotting every single company that abuses patents is simply not going to fix the problem, especially since some of those companies don't even sell products.
Look at Righthaven -- a boycott would have been meaningless, but the right case came along and Righthaven lost its teeth. And this only involved two branches of the government! Imagine what you could accomplish if you could actually pass laws to fix the patent system...