While the zone's been nerfed for marks, I just was in an instance there was a griefer purposely scanning only 2 of the 3 scanners in the Medium Exterior mission, so people could not do the mission.

Of course I switched instances, but doesn't excuse the fact that people are purposely griefing with this method.

You did the right thing. Just move on and let them play the game their way.

You can scan the last one, might take a few tries for it to succeed though.

What's more irritating is the people who run around shooting down redshirts and dragging Tholians behind them. Until the Tholians decide they want to shoot you instead.

I don't really see a problem there. Just scan the last one. A griefer in Nukara can be someone who just stands by and lets others complete the "closing rifts" mission. It counts anyone closing them.

EDIT: When I'm doing Nukara, I'm just running around, shooting everything, scanning everything. It seems to be the best method to use. Then there is the less demanding possibility to stay close to one rift and clear anything that gets close while you close the rift every time it respawns.

For Real lol I ran accross someone who had a frakin legion of the buggers on his tail it was very tragic

Nukara is full of bugs (pun intended ) so that should be more of a pressing matter than a loser who wastes their time.