How long he waited does not matter. So long as he is within the statute of limitations, it is irrelevant. You are allowed by law to wait as along as you legally want. That is why there are statues of limitation.
As for the contract, it appears enforceable. It may not be "fair" but here in America we have something called freedom to contract. The law does not protect people against their own stupidity.
The real question is: once facebook shuts down where are the stalkers, child molesters, and other sickos going to congregate?