Something like half of the recruiter emails I've been getting lately have been to the email address I have posted on github. One of them actually appeared to have scraped my commit history which was mildly creepy.

Was it a scrape for technical evaluation, or to find other committers?

It seems that if two people communicate on the internet, a third person will be interested in it.

I have no idea what they were doing to get the email addresses, I just know that I got an email that had all (three) of the email addresses I'd ever used in github commits in the 'To' line.

As far as recruiter emails go, it was not very good. Just a generic "we are hiring developers".