I don't know if the laws have changed since 1995, but back then when I worked for AT&T, you could have your telephone service turned off for using profanity across state lines.

I was actually a part of making this happen for someone who called in -- I had a high voice at the time, got called "ma'am" a lot. A male customer was coming on to me, wanted to send me flowers. As I was trying to assist them, I noticed the call records - some employee codes I recognized as males had notes like "lost call" and "customer hung up"; females had notes like "customer made inappropriate comments". Long story short, a supervisor listened in, and after they made sexual advances and used profanity, got their telephone service cut off (and I don't just mean long distance, I mean local service - the LECs in those days still had a good relationship with AT&T)...

So where's the right of free speech there?

Still not quite the same issue, because that involved federal law, whereas this is regarding Rackspace contracts... But it's an example of something trumping free speech.

The shorter and more classic example is the [lack of] right to shout "Fire!" in a crowded theatre [when there is no fire].