I'm going to take a slightly controversial position here - so please read through my logic before you downvote me into oblivion. If you read the article, you'll see that what's happening at Zynga is not "Taking Back" stock, instead it's talking about _future_ compensation. Every time I've been through a Compensation Review - one item that is made very clear to my manager, is how much _unvested_ stock I have in the co…
So, if I say "come work for me for free, and in exchange I will give you 10,000 RSU that vest over 4 years", then 3 years down the line say "just kidding, you don't get these last 2,500, but you get to keep working here", that is absolutely trying to take back comp. They can certainly withhold future restricted stock grants, but trying to take back already granted shares, vested or not, is beyond the pale in my opinion.