Where does offense end and censorship begin?

Last night I decided to rock the boat and play one of my cds at work (Black Star...Mos Def and Talib Kweli). Our typical closing mix ranges from punk...metal...80s to alternative...pop...smooth jazz. I rarely ask to have a cd played but was spurred on by having had to listen to 2 cds within the past month that offended me. A couple of weeks ago Steph played a cd which I thought had racist undertones throughout. It offended me...no...it pissed me off. I got on the intercom and asked what the eff we were listening to. I think people thought I was joking. Then, a couple of nights ago, Marie played something (who knows) with a variety of offensive lines...the one that sticks is "illegitimate son of god". I firmly believe in the freedom of speech and expression and of others to listed to whatever the eff they want to. So, my response was to bring in something I wanted to listen to and see how they liked it...politically driven rap. Rap means a lot to me from a beat perspective and from the cultural importance it has for an entire race of people. Lyrical poet is dead-on description. Well, let's just say it wasn't well received. I immediately began to hear grumblings of distaste from at least 2 corners of the store. Once we hit the "parental advisory" portion of the cd, all bets were off, and it was soon shut down by the closing manager. Was it the cussing that offended her, or the fact that she's an older white lady who can't deal wit the reality of rap? Honestly, I don't know. I know the cussing offended her and, for that, I'm sorry. However, a part of me thinks a little bit of the latter also flavored her opinion. I did apologize to her for offending her. My desire was not to make anyone uncomfortable...though I did want to push the boundaries a bit. Of course, now I'm afraid others may have to suffer for my boldness...they may shut down everyone's evening music selections...