I have a co-worker that constantly selects and re-selects text in everything from web pages to Sublime Text. I think he's developed some weird form of subconscious text-selection syndrome. He literally cannot stop doing it even when we bring it up to him.

It's really bad doing remote screensharing because the screen has to constantly redraw.

I've never seen the behavior before. It's quite odd. I never select text except for copy/cut operations.