People that use equipment as a storage place for their personal shit like keys, towel, water bottle, phone, etc.
Keep that shit with you or put it in a locker.
Doing legs today and these 4 wankers had the seats on both seated calf machines covered with their crap while they did medicine ball slams while standing on a BOSU ball nearby.
I had one set of hams left so I went and threw some plates on one of the calf machines for my next set as a little hint.
One guy walked over and started taking my weights off. I told him I just put them on there. He didn't beleive me. I told him ephatically I just put them on there as I am going there next. He was like "OK, but I better see you here next set."
I said "I will be there and if you guys would move your shit I could actually do a set!"
Worst part is they were with a PT; I was about to ask him why he would allow such horrible gym ettiquette, but in the end didn't bother as the one dude moved all the stuff before I got there.