FBI needed Libya's permission to investigate the U.S. Embassy in Benghazi

Despite journalists and witnesses simply walking into the U.S. embassy for weeks now, the FBI didn't conduct an on-site investigation until today because of 'security concerns.' They also needed Libya's permission and an extensive military escort before they could go in. 

The New York Times' Elisabeth Bumiller and Michael Schmidt report the FBI took so long to conduct their investigation because they were waiting on approval from the Libyan government. It's also a little ridiculous that they needed such an extensive escort considering everyone else just asked to walk in the front door:

Escorted by several dozen Special Operations forces, F.B.I. agents on Thursday entered the ruins of the American diplomatic compound in Benghazi, Libya, as part of their investigation into the killings there of ambassador J. Christopher Stevens and three other Americans.

...

The officials said the agents flew from Tripoli in a C-130 military transport plane and were then driven to the compound in armored cars. 

That's all a bit unnecessary when you compare it to the experience of Washington Post reporter Michael Birnbaum, who simply asked if he could walk into the abandoned Benghazi embassy. "I asked the owner of the compound if I could go in, and he said yes," Birnbaum said. (The U.S. Embassy in Benghazi is not Mordor, clearly.) CNN was able to get past the guards, too. They found Ambassador Stevens' diary. The State Department was really mad about that, but maybe CNN never would have found the diary if the State Department just asked if they could walk in like everyone else.