From this:

The FBI made secret plans to capture and arrest Osama bin Laden five years ago... federal agents seeking bin Laden had developed a plan to have a plane fly in and attack a compound in Kandahar, Afghanistan, where the terror leader was believed to have been holed up back in 1998...

But when the plan went up the chain of command for approval, it was killed by then-Attorney General Janet Reno.

"They came to the decision that this plan was probably too dangerous, that the loss of life on the ground would have been significant," Cloonan said. There was concern that people around the bin Laden compound would be killed."

Hmmm, killing people at compounds didn't seem to be a problem in other cases...

(via Croooow)

UPDATE: Hold the phone: according to "Reno Blamed for Clinton's Decision Not to Attack Bin Laden":

Former Attorney General Janet Reno is being wrongly blamed for ex-President Clinton's decision not to bomb Osama bin Laden's compound in Khandahar, Afghanistan, and the ex-president is apparently willing to let her take the fall... [speech from last year in which Clintion admits it was he who made the decision not to arrest OBL.