For coders, check commit logs and the like. They can email cat video links to each other all day long for all I care, but if their last commit was last week then we've got a problem. IOW, you don't cut down on the shenanigans, you make sure the work is getting done. As it often turns out, if there's a lot of cat video links there probably isn't a lot of work and vice versa.

Were I appointed to be king, if you're noisy then STFU, full stop, whether you're getting your work done or not. Indoor voices, people, or take it somewhere else.