There's a bit in the law text that supposedly penalises bad DMCA requests (ie the sender must consider if it's fair use, etc) but it's turned out to do nothing in practice and for example fair use covered stuff on youtube just gets repeatedly DMCA'd even if by some miracle the target has the time and energy to try to counter it.

(A concrete example I remember off the top of my head is on a blog that doesn't welcome HN links...)