In a former job I hired a ton of front line employees. I encountered a few applicants who chose to leave when drug testing was mentioned and more that never showed up for testing when contingently offered. I had one guy who failed to show up for an interview, gave us a sob story about why he couldn't make it and then failed to show up for a rescheduled interview. He then proceeded to go ballistic when we told him we would not be rescheduling again. Neither time did he even bother to call to let us know before the interview or even call in to let us know what happened the same day.