don't pull the stupid "it's not in the tos" shenanigan.
willco, add a clause to the tos just to keep folks who like to excuse a lack of common sense from pullin' the whole "bubububububut it's not in the tos, it should be okay you guys because you didn't think of it and enumerate it" crap
like "5. Use common sense. Ask yourself: would I want a coworker to see this image on my PC, or catch a glimpse of this text? If what you post can't pass this litmus test, STOP. Or, much like littering in the state of Washington, it will hurt."
edit: I should add that I laugh at the inappropriate; my humor is completely wired for it. That's not an excuse to SHOW me it.