A security clearance is somewhat difficult to get and not especially hard to keep (Snowden). However, having a clearance then opens you up to an entire industry. During tough times (2008) that means jobs will be available:
https://www.clearancejobs.com/
The background checks are thorough. We've had many in the family (definitely not me), my dad, two of my brothers, two uncles, my ex-girlfriend, brother in law, .... And then we get listed as personal references which is a real pain. A drug conviction will not blackball you but then you have to be completely honest as they will find out and that will blackball you. Debt is a biggie.
https://www.state.gov/m/ds/clearances/c10978.htm
As for the article, I think the inferences people are making are reasonable. Also, given Facebook's scope that they need people with clearances seems reasonable.