When there's a long 'queue' of cars moving along in the outside lane patiently waiting in line to pass whoever is clogging up the middle lane miles up ahead. Then some selfish cretin decides they are too important/late to observe the highway code and speeds past inside on the middle lane and tries to cut back in further up. That is my biggest peeve.
So AIBU to wait until I draw level with the cretin who is feverishly looking for their opportunity to pull back out into the outside lane, and ostensibly block them in by maintaining the same speed as the person in front of them in the middle lane?
I admit to a fission of power and satisfaction watching as the car in front of me gradually pulls away, leaving a tempting tiny slice of space in front, but not enough for the cretin to pull out. I usually wait until the vehicle behind me is suitably positioned to pass the cretin without letting them out either, then I floor it. Haha. I'm a shit and I know it. The cretins drive me to it though.