I worked for CollabNet from 2005-2010. When I left, I bought my stock options. I got a friendly letter in the mail a few years later telling me that the company had been restructured, and that my shares are now worthless. If I'm getting shares as a part of equity, then I'll consider that as part of my comp package...however, if they're stock options, I generally completely disregard them: I haven't yet met a startup…
Can anyone chime in as to how it is legal to remove someone's ownership from a company like that?
Old company is renamed something like "legacyabc"
A new company is formed with the old company's name. All personnel and IP is moved to the new company", all debt is left in the old company. Original share holders get a big payout.
The old company is now worthless. Shares are now worth less than the original strike price. Original company is likely dissolved.
Bad luck.
Generally you'll have to sign a new contract in the new company to keep working.
If you're really unlucky, your L1 (or w/e) visa is tied to the old company, you now have to leave the country, and can't easily transfer to this new company.