I'm not a lawyer, so take all this with a very very large grain of salt. I did some reading about this because I had some mild concern about a couple side proj

I'm not a lawyer, so take all this with a very very large grain of salt. I did some reading about this because I had some mild concern about a couple side projects, and basically, if you're not charging money and there isn't anything intentionally malicious about your web site, people will have a hard time winning in court. If you're giving away an opt-in service for free, even if someone tries to sue you, it will be very difficult for them to win. If they were paying you, and their business relies on your service, then they may have grounds for a lawsuit (assuming you didn't do anything to remedy the situation or didn't react appropriately). But if you're giving something away, it's viewed as their fault for relying on your service when it didn't have any type of guarantee associated with it. Web sites have bugs and downtime -- that's an inherent problem with computers -- so unless you make a guarantee that you're providing a bug-free 100% uptime solution, you don't have any obligation to provide a service that exceeds the reliability of even the most advanced multi-billion dollar companies (does anyone have 100% uptime and no bugs?).