This is why DMCA is broken. Too easy for false claims. It’s plagued the music industry, YouTube, and now free software.
Why is it that as citizens we are powerless against such clearly broken laws as DMCA? Can't we do something about the situation, declare it unconstitutional or something?
It's not obviously so - which articles/amendments do you think it violates? In any case, it's insufficient for us to declare it unconstitutional, that's for a judge to decide. In the absence of such a ruling, we can elect legislators to repeal it. But that seems terribly unlikely unless you can pose new legislation to take its place.