Judging by the membership-ID on my ScrumAlliance profile page, I reckon I was one of the first few thousands to take the certification. I openly blogged about it at the time, I dare say with a hint of skepticism, and since then I've never really flaunted it (well, maybe now I am).
I just saw a nice analogy for the CSM, paraphrasing Jon Kern:
To filter out potential employees by checking their certification, is like seeking out race-car drivers by checking if they have a driver's license.
I don't want to support this unwarranted prestige of being a CSM any more, so I've taken the notion of CSM out of my résumé, and I recommend everyone else to do the same.
If I'm hiring, and you flag your CSM title, I'll rank it as bragging, and that your CV is well inflated.
If you're a company looking to hire me, and you filter out non-CSM candidates, I don't want to work for you anyway. Thanks for not wasting my time!