It’s rare I disagree with XKCD, but the first amendment protects you from all forms of retaliation from the government over free speech, not just arrest. The government can’t censor you, or raise your taxes, or harass your family, or sue you for damages over something you said (with some very well defined exceptions).
Ultimately, the government is the entity that has to enforce this contract so I don’t know that it’s completely outside the purview of the first amendment. For example, not so long ago, the Supreme Court ruled that protestors can’t be sued for emotional distress on free speech grounds. Essentially, because of the first amendment, the government isn’t able to award damages over the exercise of free speech. That would seem to apply here as well.
The only question is can you sign your right to free speech away in a contract if you’re merely a customer, and just how liable can you be for breaching an agreement of what appears to be $5 worth of service.
