Look; it's not ILLEGAL to strike. Meaning you can't be dispersed by force or arrested for doing so. But the fact that it is not illegal does not equate to absolvement of responsibility. You also have the right to form a union and engage in union activities, but try standing on a soapbox at despatch and you'll quickly learn where the rights of workers collide with the rights of employers.
it's not illegal to speak your mind either. In fact, you have the right to free speech. However, making a public proclamation on the evils and stupidity of your employer will get you fired regardless.
Again; if you're going to strike, make sure to do it on your days off.