Er, isn't this just a case of age discrimination?
The Equal Employment Opportunity Commission isn't yet involved - because the Thiel Foundation is not technically an employer?
Assuming this is a serious question: the Thiel Foundation may be an employer, but it's the other side you want to look at--fellows are not technically employees.
Peter Thiel is offering another round of "20 under 20" Fellowships. The application deadline is December 31st. We know many of the current Thiel fellows here in the Bay Area, and it's a great opportunity. Here's the official letter from the Thiel Foundation: