Referer Spam: A message to writers of web tools
I've written about this before. So has Mark Pilgrim, and he's got a much bigger audience than me. If you are writing a news aggregator, web robot, blog indexing tool, whatever, you MUST NOT advertise your product's website in the Referer header. If you do, your product does not comply with the HTTP standard. More importantly, you're being incredibly annoying. →