The entire country (outside of corporate boardrooms) seems to be up in arms about all the stores being open on Thanksgiving, which is traditionally a national holiday. It all started when Wal-Mart, that bastion of worker abuse, announced that they were going to beat "Black Friday" by a day, and everybody started following suit.
The answer is fairly simple, though. If you don't like stores being open on Thanksgiving, don't shop on Thanksgiving. Tell all your friends not to shop on Thanksgiving, and explain why. Social media is an important part of this: send out the word on Facebook and Twitter, post videos on YouTube and Vine, or even post a message on Google+ (if you're particularly fond of the sound of your own voice echoing off empty walls).
You can even slant your message to match your audience. "Abusing the workers" won't resonate with the Fox News crowd, but "destruction of American values" seems to do it for them.
Protests might work, but you'd be giving up your holiday at that point, and it's a little late in the game for that anyway: you aren't going to get massive crowds to help you out. So the best way to get your message across is through your wallet - by not using it. If the profits for sales on Thanksgiving don't pay for the employees to come in that day, the corporations aren't going to do it again.