Jackpot, Sly! Look at all this stuff! Must be worth millions! And you know what that means... tighter security. You're going to have to be extra sneaky to get the treasure key here.
― Bentley advising Sly to be sneaky in High Class Heist[src]
Once Sly entered into Raleigh's personal quarters, Bentley was amazed by all of the objects in the hallway, claiming it must have been worth millions, which also meant tighter security. As most of the place was heavily secured with lasers and spotlights, Sly had to be extra sneaky if he wanted to successfully swipe another treasure key.
Whoever thought this code up knew what they were doing. Dial in 4-3-6.