Yes, American employers are pretty terribly paranoid when it comes to nipples. What it boils down to is they adopt a strong policy as a defense against lawsuits, so if they are ever dragged into court by an employee claiming a 'hostile work environment', they can point to their policy enforcement as proof that they aren't a 'hostile environment'. In practice the policies don't just ban porn, they ban anything that could possibly make anybody feel uncomfortable or objectified, so swimsuit calendars or even dirty jokes can get you fired.

So the upshot is, if a site isn't careful about identifying links to naked photos, it is no longer safe to read it at work. Even some sites that sometimes have racy ads are best avoided at big companies (who tend to have bigger legal departments, lawsuit exposure, and stricter policies).

http://en.wikipedia.org/wiki/Hostile_environment_sexual_hara...