Tucked away in the reconciliation bill now bogged down in Congress is a requirement that banks report the annual deposits and withdrawals from every bank account that has activity of more than $600 a year. It would not list individual transactions, just the total money flow in and out.

Ostensibly, this is to catch rich people who have been under reporting income. Secretary of the Treasury Janet Yellen gave as an example: “High-income individuals with opaque sources of income that are not reported to the IRS, there’s a lot of tax fraud and cheating that’s going on.”

Wages, salaries and fees are already reported to the IRS through W-2 forms. So is investment income. That sort of income is what a large majority of American families depend on. So their ability to under report income is very limited. Yellen says she’s after high-income individuals, noting that, “If someone reports an income of $10,000, and they had $3 million go out of their checking account, that tells the IRS that’s an individual that you might audit.”

To be sure very high-income individuals have many ways to lower the taxes they have to pay, many legal and some illegal. Several present and former members of the board of the hedge fund Renaissance Technologies recently agreed to pay a whopping $7 billion in back taxes and penalties. The founder of the firm will pay an additional $670 million. (There is no need to set up a GoFundMe page for him. Forbes magazine estimates his net worth at $25.4 billion.)

But the proposed reporting requirement would not have caught this tax evasion, as it involved the improper use of a means to convert regular income into capital gains, which are taxed less heavily.

The federal tax code is littered with quiet favors for the politically influential and major donors. And, of course, the rich have the most sophisticated tax lawyers and accountants.

If an individual owns a sub-chapter S corporation, for instance, many expenses that most families have to pay for out of after-tax income, such as an automobile, can be paid for by the corporation, thus out of pre-tax income.

And even in these days, there are not that many billionaires. Forbes says that there are about 600 Americans today with a net worth of more than $1 billion. The IRS would have no problem auditing all of them and, for all I know, already does.

So who is the real target of this unprecedented intrusion into the private lives of nearly every American? After all, with the reporting limit as low as $600, only small children learning how to save would escape.

It’s not the rich the Feds are after. As always it’s the middle class. It’s those living, partially or fully, in the underground economy, making use of barter arrangements and being paid in cash.

It’s not uncommon for, say, a plumber to do plumbing work for his electrician, who does electrical work for his plumber, with no cash changing hands. The new rule would not catch this sort of mutual back scratching.

People who earn much of their income in tips — waiters, hairdressers, taxi drivers — don’t have that income reported to the IRS. People such as cleaning ladies and lawn-care guys are often paid in cash. Day workers, many of them lacking green cards, are almost always paid in cash. Many of these people, and there are tens of millions of them, earn good incomes, some of them very good incomes indeed.

If this new reporting requirement goes through, these people will face a choice. They would either have to pay taxes on this previously unreported (or under reported) income or stop using banks to hold it. I expect that many of them, their consciences untroubled by cheating the IRS, will stop using banks, or find ways to launder the money.

So the $600 reporting requirement is in fact just one more example of the Washington art of taxation described by the late senator Russell Long: “Don’t tax you and don’t tax me. Tax that man behind the tree.” The man behind the tree is always the rich, “who don’t pay their fair share!” And as always, it’s the middle class that they really after. After all, that’s where the money is in this middle class country.