Negative. I live in Madison, WI, where you might have heard on national news a couple of months ago with the MASS amount of recalls of Republican House members due to protests against them because of the "Budget Bill" that Governor Walker introduced illegally. Protests do a SHIT-TON when you have the momentum behind them.
However, protests against Corporations are a different thing than a protest against Government. Government members get their jobs from the people, whereas Corporations, well, it doesn't matter if you protest against them, nothing will happen to them. Corporations have become way too smart by dividing their companies into smaller entities and controlling the media. Go here for instance http://www.cjr.org/resources/?c=disney . (betcha you didn't know Disney owned 80% of ESPN) Although it may be media related, the same is true for almost every other corporation.
One person that holds up a "Fuck the Troops" sign in a protest WILL become the image of that entire group due to the media's focus on that one thing. The common American is not smart enough to divulge the information needed to realize that one person does not define an entire group of individuals.
Edit: Oh, and btw, the recall of Governor Walker is starting 11/15/11. Although I don't think he'll get recalled, and if he does it'll be ridiculously close, it'll still be a national momentum shift in Democrat-Republican values.