Blatant disregard for preserving people's hearing. Most of my coworkers are of the opinion that not wearing hearing protection while operating loud tools and equipment (chainsaws, pneumatic drills etc) is not a big deal. What's worse they will often not bother to give a heads up to people working nearby that they are about to start. As a musician, and also someone with a family history of hearing loss, this kind of behavior pisses me off