Yes, ideally if your client is capable of reporting you can contribute by reporting them.

How it works and if anything is done with reports depends on what your using, for example some clients may block things that are reported by people you follow but not followed by people you follow. Its a bit of a self police in that regard at the moment.

I have been pleading for a ban list feature where we can subscribe to blocklists that are maintained by people we trust (Think adblock style), but I am not a dev so I haven't been very succesfull in my advocacy for that feature.