I think that you are significantly wrong. Subtitles are a derivative work of that which they are created from and should be covered by that copyright. The creator of the derivative would have a copyright on that derivative but that does not permit them to distribute it without the original work's copyright holder's permission (and the original work's copyright holder would need the derivative's copyright holder's permission to distribute that.

It may be however that there is a fair use argument that could be made in many jurisdictions (based on the intended use being by a licensee of the original work, the accessibility benefits and the (presumably) noncommercial nature of the operation).

I would strongly oppose police enforcement rather than civil action and even that would strike me as a bad commercial practice by the movie companies. It would be better to either ignore the practice or even endorse it in some way as there is no significant profit to be won by fighting and plenty of goodwill to lose.