Tagging, when will you grow up?

This post discuses the future of tagging, and makes some suggestions for how we can possibly maintain it going forward. Having spent a lot of time dealing with keywords and synonyms, it’s painfully obvious to me how hard it is to be both flexible and useful. What if I tag the contact page of a place I’m going to with address, but someone else tags a page because it talks about spoofing a MAC address. Or what about that keynote speech that someone saw on YouTube? Where do you draw the line?