I think it's most likely that we know where he is, and as long as he's not able to run things, we're leaving him alone. Maybe that's giving us more credit than is due, but I find it hard to believe that the trail really is cold.
not a chance.
Our intelligence capabilities are good but it's not the "tin foil hat" sci-fi stuff so many numb skulls believe.
We couldn't help Danny Pearl, we can't help so many of the hostages that have been taken in Iraq and we couldn't find the missionaries held hostage in the Philiipines etc..etc..
OBL is alive and well and he may be for years.