I think we already have a few - the trouble is that any general thread of that kind tends to spiral into a discussion about hackers, what they can trace about you or how to get hijacked - and whether you should do anything interactive at all on the web. But this thing I'm onto isn't primarily about hackers - the tagging was totally open, though often invisible to me as long as the file was on my own hard drive. I'm trying to get more about this, so please feel free to comment and share information and know-how!