Also worth pointing out that in 1999 Yahoo bought Geocities for $3.57 billion in stock. Geocities had a similar audience and premise as Yahoo - it made building and hosting simple websites easy.
Check out this almost $6 billion redirect, http://broadcast.com.
Hope the Geocities founders cashed out in time (and weren't locked into unvested shares). I'd hate to get a tenth of the agreed upon price for my company.
http://investmentxyz.blogspot.com/2006/05/cubans-collar-anat...
Some companies even prohibit selling covered calls, regardless of strike price. (A deep enough in the money call behaves somewhat like a put.)
I'm a little surprised that Cuban would be locked out of selling the shares but able to enter into the collar. I'm sure it was legit (since it's well known), but still...