GitHub is definitely a good tool for hiring,it is easy to measure using real-world code and discussions than using a whiteboard or coding excercises
Problem is when we use it as filter, an active GitHub profile typically means that person is good in coding, but an inactive or dead GitHub profile is neither good or bad sign for hiring decision. Do GitHub for filtering candidates only if you can afford large number of false negatives
We're a place where coders share, stay up-to-date and grow their careers.
We strive for transparency and don't collect excess data.