And where that government action might lead is to some high-profile, or at least high-net-worth cases. They’ll make the big splash, and the others will crumble.

“I think the people in the crosshairs are the people who the government believes took money out of the country—large, vast sums of money,” he said. “You go after the biggest fish and everybody else falls in line.”

Boggs, whose Los Angeles firm deals with tax settlements, said he’s been talking to plenty of upset individuals about the U.S. Government’s efforts to go after offshore accounts.

“These are people who really feel that the rug has been pulled out from under them,” he said. “This is the superrich, so they’re not used to hearing ‘no,’ they’re not used to hearing ‘bow down.’ This is a tricky demographic because they’re used to getting their way, and they’re not used to taking one on the chin from Uncle Sam when Uncle Sam has been looking the other way for so long.”

But those 20,000 or more people the government’s trying to scare into coming forward aren’t just the superrich.

“They are a lot of different categories of people,” Clarke said.

Clarke broke the people with Swiss bank accounts into three different categories. There are those whose grandparents or parents deposited money in the bank many years ago—perhaps as they fled the holocaust—and who have never moved the money into the U.S. Then there are those who worked abroad, who might not have been U.S. citizens at the time they set up their accounts, and who left the accounts in place when they moved to the U.S. The first two categories may not be big-money players, and they probably make up the majority of those with Swiss accounts, Clarke said.

Finally, there are those with the piles of money.

Playing big in real estate money. Hit it big on an IPO money. Hedge fund manager money.

“There’s the third category, and that is the people who earned the money in the U.S. and affirmatively pushed this money into Swiss accounts,” Clarke said. “Those are the people the government would love to get ahold of.”