He could have 100,000 bitcoins in his wallet and he will have trouble converting them to anything other than bitcoin because the NSA and every other intelligence agency is on him like fly on shit.

The second he tries to cash out an account at Mt.Gox , CampBX or any exchange for that matter  it'll get seized.  They would most likely let him sell his bitcoins but not withdraw,  so at the end of the day he'll have neither bitcoins or dollars (or Euros, Yen, whatever).

He's going to have to find lawyers that accept bitcoin,  food stores that accept bitcoin,  etc... because he most likely won't be able to convert it to anything else.   Technically doable... but boy he has his work cut out for him.