Personally I would love to receive something like that message.

I consider (And share in my CV) my stackoverflow, github, and linkedin are good representation of what I can do as a professional and thus I am careful with what I share on those. Meetup might be a stretching it a bit if you also use it for hobbies and you don't like sharing those on your CV.

This guy has done his homework, and has checked a lot of sources to make sure YOU fit the position before contacting you, that takes time and that time is his company's money. So frankly I would take it as a sign of a company that really gives a lot of F*cks about who works for them.

Again depending on how you use Meetup he might have overstepped a bit. For example mentioning your facebook, google+ or others might have been too much for me too.

> Should I reply and complain to this person? Or am I overreacting?

Yes, you're overreacting, it goes with the territory for talent in a hot space. Linkedin response rates are down due to user fatigue. But I'm also wary of messages that come across as recruiter cat-phishing.

Assuming his firm looks legit. Ask him to first forward a detailed position summary for review. You can then make an informed decision whether to dialog any further. Make him earn the conversation.

This may have come from a site like talentbin.com, which gives recruiters a keyword search based on profiles from Github, StackOverflow, etc. I worked on a competing site for a bit until I decided it was a force for evil not good and shut it down. My site was pulling data from about 20 online communities, among them Github and Meetup.

Consider the alternative: "Hi, I think you might be a developer, but I haven't looked at any of your public stuff, and yet in a thinly veiled attempt to make it seem like this email is personalized, I'm going to tell you I think you're a particularly good fit for this role, which involved [buzzword], [buzzword], and [buzzword]!"

Would that be more to your liking?

Github and Meetup are inherently social, default-public communities. You should consider it a sign of respect -- or at least a signal of intent -- that someone's taken the trouble to actually review your stuff.

You should make your stuff private if you are uncomfortable with the entire internet having easy, open access to it. If the sites/services you use don't have appropriate measures complain to them or use something else.

There's really not much point complaining, you might stop that person but not the actual process he's using.

http://bitbucket.org/ has unlimited private repositories for teams under 5 which is a great way to sandbox non-public projects.

In the GitHub case, I have no repositories. I only view other projects and sometimes download them. Is that information public? I don't see where.

View your profile in incognito mode and you'll see what's public or not.

If you are 'leaking' information this way you can avoid it by anonymously cloning projects to elsewhere, and not commenting or w/e interactions are broadcasted. Github has really shitty privacy controls so I don't think you can conceal yourself very much while using their service.

I believe even if you don't share your email address on Github, someone can still pull it out of your commmits. At least that used to be possible.

Better than the usual...

   "I see you are a .NET Developer. I have a excellent 
   Java role that I think you will be interested it."