I don't know the biggest seizure from American OC members,but to speak to your other point, I believe that the Feds can take not only personal assets,but anything that was acquired with the proceeds of illegal activity.

Even if they own a legitimate business,if the business was started with illegal funds,they'll grab it.

Here's an example from my neck of the woods: When Junior Williams,(the numbers kingpin) got convicted, the Feds took the following: More than $4 million in cash, condos at the Seven Springs resort, a bass fishing boat, a SeaRay boat, a Rolex watch, the ‘Ponderosa’ hunting lodge in Tionesta, a BMW car, two Mercedes Benz cars and the Hotel Tidioute.