According to the article, this is about employees with unvested shares. That means they don't actually own the shares yet; they're only promised the shares if they meet certain conditions, usually continued employment. If they're at will employees, Zynga has the right to fire them at any time for any reason, including firing them to keep their options from vesting. That may be sleazy and underhanded, and it's likely to cause them serious loss of reputation (more of a problem for the VCs, who will have to deal with other startups, than Zynga), but it's technically legal. Demanding the return of the options is just giving the employees a choice: get fired and lose your options because they haven't vested or keep your job and give up your options as the price of continued employment. Again, it's sleazy enough to make pond scum resent your comparison to Zynga management, but it's probably legal.