Yes! You could easily sell users a service that helped them hunt down and delete their old embarrassing geocities sites, if you could figure out a way to confirm that they are indeed the authors.
People could use google, but you could put extra work into brewing up some special sauce that would, for example let them find their sites with only a combination vague memories, such as their neighborhoods, or when they created it, or the types of things they linked to, or the background music their site had (mine had the mission impossible song) or the type of content (mine had lots of animated gifs). Google wouldn't care enough to do that.
If users find their content on their own, they can always request it to be removed, all you're selling them is a tool to help them do it.
I wonder if people would really pay for it? It would be fun to find out. I would help build it
That's evil genius thinking right there. There are some newsgroup postings Google has archived for eternity I would pay good money to get rid of.
Hosting this might get expensive after a while, are you going to put up ads anywhere or do you plan on eating the cost???