I really like this. I don't mind Internet acting like the Wild Wild West but I do mind there's no accountability. This is a nice way to pass the economic burden to the crawlers for sites who still want to stay freely available. You want the data, spend money on your side to get it. Even though the downside is your site could be delisted from search engines, there's no reason why you cannot register your service in a global or p2p indexer.