Tony Rezko is one of Obama's closest friends.
The fact that you know nothing of the case says a couple of things.
1) You're avid Obama fans and not inclined to go looking for information that would soil your vision of him.
2) The mainstream media has refused to say anything bad about Obama.

Obama allowed this convicted fraudster to purchase the grounds to his home for him while Rezko was already under indictment.
You really should know this stuff.