[pluma]

Supposedly you risk jail time when submitting illegitimate DMCA claims. In practice the only case I know of is when YouTuber thunderf00t used that threat against another YouTuber (VenomFangX) to make him publish a video statement clarifying that his claims were illegitimate and he won't do it again -- but none of that ever ended up in court (because VenomFangX complied, before temporarily retiring from YouTube in shame).

EDIT: Of course the ContentID system probably circumvents that entirely because technically your content is taken down automatically rather than because of a DMCA claim. Even though the effect on the uploader is the same: impacting the monetisation of a video they may have invested a significant amount of time into. If anything it's worse because there is no built-in way to counter-claim or claim damages (without directly going to court).