The current system as it is being first come first serve is already fine as it is. As it was pointed out before, seniority already gets your vacation and then your schedule every month. Being able to manipulate it live is a huge plus for everyone. There was already step trading where the senior folks were able to make their perfect schedules, but now with PBS, you can just do it straight off the bat. The simplest solution is putting in some sort of captcha before you hit submit to at least get rid of the script kiddies bots.