The worst abuse is when they set short project deadlines without any attempt to match the workload to the available staff, and then expect people to work extremely long hours to meet the deadline.

A occasional long workday to get a critical task done is one thing, but when people are put in a position where they are expected to work long hours for weeks or months, then that is just abuse.

I see this coming on a project that kicks off next week. The plan was put together by non-IT people who made no allowance for the considerable programming time required, no allowance for time to purchase and setup new systems, and no allowance for the fact that a number of key people have significant vacation time scheduled.