Reading a Confluence document, there are per-paragraph comment icons to the right of each paragraph. Of course, they're invisible until you hover over them. That's awful UI to begin with.
But then if you do hover over them, it automatically selects the text of the whole paragraph. Or it tries to; it actually only selects the first part with default text styling. But why is it selecting at all? That's also horrible UI.
But in addition to just selecting, the little comment dialog pops up over the stuff that was selected, effectively inserting text into the middle of what you're reading. Also terrible UI.
If you then move your mouse pointer off the icon, it deselects the text. Actually, it only does about 70% of the time. Sometimes when you move off, it fails to deselect and just leaves that text highlighted.
I just spent about five minutes trying to figure out why my mouse was clicking on its own. (Keep in mind everything above involved zero mouse clicks. It's all just mouse pointer motion, or even just scrolling.)
Are you guys trying to develop user-hostile UI?