I've been a big fan of specialty job boards for recruiting developers. I use Elance mostly, but I subscribe to CodePen, Github and Stack Overflow as well. Several of us here on Staffing Talk have written about our success with these sites.
It seems, though, like all good things in recruiting, that any great resource ultimately succumbs to abuse from the masses that come to exploit it.
LinkedIn has become an email spam platform. Craigslist suffers from garbage postings. I don't find either very useful any more. Who was it (Yogi again?) who said "It's so crowded there no one goes there any more."
Github has enjoyed a great relationship with developers until this last month. The controversy won't cause it to become less reliable for recruiting immediately, but it certainly can't help. If developers don't feel they can trust the site, they will go elsewhere. If the money guys start demanding more revenue by letting recruiters loose to hit on devs a la LinkedIn, the site will lose its mystique and the devs will go elsewhere.
The latest to fall prey to the masses is Stack Overflow. There is a lot of hate going on there because of people that abuse the site to falsely establish reputation points for themselves. See "Why Is Stack Overflow So Negative as of Late" for the lurid details.
Ultimately, the rapidly declining utility of networking sites is good news for professional recruiters who build and keep a private community of candidates and can pick up a phone and truly dig for a short list of great candidates.