We had some contractors in a Mexico office that would sometimes visit San Jose (CA). At a certain point, one of them decided to permanently relocate to the US. Most things were fine, but there was one social line he crossed that needed to be said. His computer desktop background was pretty much laden with boobs and asses. The background image was pretty much intensely horrible. Another co-worker and I just calmly explained to him that he can choose any background he wanted as long as it didn't potentially land him in trouble with sexual or racial discrimination issues. Definitely, in this case it was an easy conversation and he obviously fixed the issue immediately.