It was not the usual Congressional scene in room 2237 of the Rayburn House Office Building on Tuesday afternoon. More people in the audience than usual had hair dyed pink or green, and opted for T-shirts instead of button-down attire. And the name tags on the table in front of the room sported an unusual set of monikers: Kingpin, Mudge, Weld Pond, and Space Rogue. The occasion was a reunion of four members of the hacking collective L0pht Heavy Industries, almost 20 years after they warned of rampant insecurity online in the Senate’s first cybersecurity hearing.