Not just ignoring flight crew advice and common sense to generally stay buckled in order to gain maybe a minor amount of comfort and convenience being unbuckled, but unbuckling even when the seat belt sign is on and again common sense says being buckled in is the smart move. On my most recent flight I heard quite a few people unbuckling their seat belts while the plane was still rolling down the runway after landing. You couldn't wait 5 more minutes until the plane is at the gate?
Also: people clapping the second the back wheels touch on landing is particularly hilarious to me because it implies an acknowledgement of the precariousness of flying, but a complete ignorance of the fact that you're just entering the second most dangerous 30 seconds of the entire flight.
Only aviation professionals or recovering flight phobics like me who have watched every episode of Air Crash Investigation will take proactive safety measure of their own accord. To normies it's all just a pointless hassle.