Yahoo! Indexing New Sites via Whois Data?

Reports come way from WebmasterWorld that Yahoo! is indexing new sites via whois data. One member reports;

I registered a new domain mid August and put the in-development site live a week later. I had no reason to look at logs until today - no links in and no submissions. I've just noticed that Slurp came by last week. It followed hot on the heels of a Whois IP. Is this normal of Yahoo! to check out newly registered domains.

We have discussed a bit in the past on speculation on how Google Finds Newly Registered Domain Names.