Naked theft is blatant larceny.
Or your manager could fail to buy you the futon and sheets your contract said you should have. Both are theft. But after six months of watching and hanging around with your coworkers, you come to realize that everybody else has some private lessons on the side. In your legitimate job, you start having more and more free conversation to use up time. Maybe you make international long distance calls or faxes on the office phone or use the school's photocopier to copy your resume.