Possible Clues:

• Curious surrounders
• Threatening group
• Torch-wielding group in "Frankenstein"
• Mafia, informally
• Master of Ballantrae opens in Ring?
• Gaggle : geese :: ___ : emus
• Rowdy bunch
• Feds' focus
• Flash ___ (sudden gathering)
• Soprano's group, with "the"