Recruiter here, and for the record I don't care what someone is currently making. What I really want to know is how much you are looking to make, because if your expectations are not reasonable it is a waste of everyone's time to move forward.
That said, I will often ask what someone is currently making, but I usually ask it after asking about their expectation. My reasoning is to try and provide some context to the expectation. If an intermediate engineer in Philly (say market value of 90K) says he/she is looking for 150K, I'll ask current salary to try and figure out why the expectations are so far from market. There could be several legitimate reasons (contracting, employer overpays, etc.), but without one I know the person I'm dealing with is unreasonable.
The article comes across as paranoid though. I say/write this a hundred times a year: If you know your market value, you don't need to worry about "who talks first" or providing current salary. College students make $0 a year until they get their first job - does that hurt them in negotiating with companies? Not if they know market rate for entry-level jobs.
The first bullet point in the article ("you've blown your negotiating position out of the water") is simply untrue, the second ("passed info to company and recruiter") doesn't matter, the third echoes the first (again, untrue), and the fourth ("underwater price fixing") assumes quite a bit.
I genuinely don't care what someone is currently making (with the exception stated above), but I disagree that providing that information is harmful to negotiations for anyone who knows their market rate.