What are some examples of unethical behavior in the workplace?

Be it the government or private sector, the unethical behaviors I've seen most consistently are,

Petty thievery. Taking office supplies home. Paper, notebooks, pens, sharpies, you name it, I've seen people swiping them.

Gossiping about colleagues behind their back, usually badmouthing them.

Taking time off by lying about sickness (oops, well enough to walk around in the neighborhood while out sick).

Work hours/Time-sheet manipulation.

• Taking care of personal business on work time.
• Pretend to work on the computer. Instead browse the internet for non-work related stuff, especially online shopping, but log in time-sheet as work hours. Obviously this workplace didn't track internet usage.
• An unusual one in a basic research lab, show up to work only late in the day, say by 7 or 8pm. Boss thinks person is a night owl but in actuality this crafty post-doc would usually leave by 11pm or 12am, rarely staying until 2am.
• Take numerous coffee breaks throughout the day, ostensibly to discuss work-related matters but more often it would be just shooting the breeze.

Currying favor and its usually predictable corollary, blatant favoritism. Like a weed, seems to flourish in all kinds of workplaces of all sizes. Damages morale yet vanity being an inextricable part of human nature, this one will stay par for the course.

• In a basic research lab, this took the form of the favorite(s) canceling or swapping their data presentation or journal club duties routinely, typically at the last minute, without incurring any penalties while non-favorites experienced an uncompromising feet-held-to-the-fire pressure to comply with 'mandated' policies.

Currying favor and attendant favoritism are unethical because they disadvantage employees who don’t engage in such shameful behavior.

https://www.quora.com/What-are-some-examples-of-unethical-behavior-in-the-workplace/answer/Tirumalai-Kamala