I do. I have a lot of scrapers, and I don't want to be responsible for what other people do on their sites in case my pub ID happens to be scraped there too. So that's my way of disavowing anywhere my code appears that I'm not in control of.
Someone scraped my site a couple of months ago and put my G-rated content and ad code on an awful XXX site. In cases like that, I'm happy that Google knows I never gave permission for my code to be on that kind of site.