Greg Smith, author of a new Wall Street tell-all that accuses Goldman Sachs, his former firm, of ripping clients off, says the financial crisis and new regulations have done little to curb bad behavior on Wall Street. In fact, in Smith’s opinion, they’ve done the opposite. “It’s absolutely gotten worse since the financial crisis,” Smith told Fortune when we caught up with him before a ping-pong match in one of his first interviews since finishing the book.

You probably remember Smith, or have read about him recently. He’s the former Goldman banker, who, earlier this year, quit his job via the New York Times. In an opinion piece, Smith wrote that the culture at Goldman had turned “toxic,” and no longer one he could be a part of. He said bankers at the firm openly talked of abusing clients, who Goldmanites called “muppets” behind their backs.

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But the piece was light on details. Smith’s new book, which is titled “Why I Left Goldman Sachs” and comes out on Monday, elaborates on the op-ed some. Smith says during the financial crisis, Goldman charged clients a huge fee, up to 20%, when they wanted out of an investment that was pitched as ultra safe. He says in the summer of 2011, when the European debt crisis was at its worst, Goldman regularly pushed its clients into, and out of, investments tied to banks in France and Spain. Often the firm was taking the opposite position of what it was telling clients. Goldman’s best accounts were told to steer clear entirely.

More recently, Smith says, Goldman and others have been trying to sell pension funds a complicated derivative that carries high fees, but offers little more than the asset allocation advice you would get from a run-of-the-mill financial planner for much less.

In general, Smith paints a picture of Goldman as used-car salesman. Clients who didn’t verify prices often paid much more than they needed to. When clients made mistakes, Goldman corrected them to the firm’s advantage. The result is that Smith says Goldman’s least sophisticated clients, which Smith says are often the managers of pension and mutual funds, who invest money on behalf of firemen, teachers and regular individuals, get the firm’s worst products at the worst prices. Hedge funds, which typically work for the 1%, get Goldman’s best advice.

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But while there is plenty that appears ethically wrong, nowhere in the 250-page book is any real evidence that either Goldman or anyone at the firm broke the law. Goldman says its own investigation following Smith’s March op-ed piece turned up no evidence of wrong-doing. In the week leading up to the publication of Smith’s book, Goldman leaked an internal report that Smith had asked for a million dollar bonus and a promotion a few months before leaving the firm. Both were denied.

Smith calls Goldman’s allegation that he quit over pay a total fabrication. He says his bonus was hundreds of thousands of dollars, and that it was more than most of his peers. “Of course, I asked for more,” says Smith. “Everyone does.”

Smith says the fact that Goldman can claim it did an investigation and found nothing wrong is a problem with the law, not his account. “The frustrating thing is that much of the behavior that I describe in the book is legal. Unethical, but not illegal.”

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Smith says things have gotten worse since the financial crisis. According to Smith, many of the activities that took advantage of clients paid off during the financial crisis for Goldman. As a result, he says, many of the people who took that road have wound up in leadership positions at the firm. What’s more, at a time when investment banks are seeing their profits pinched, firms are more willing to turn against their clients for a buck.

New regulations may also be adding to the problem. Before Dodd-Frank, Wall Street firms used to wall off their proprietary trading groups – the divisions that make risky trades with the firm’s own money. Now that activity has been relocated to the desks that are supposed to be focused on buying and selling orders for clients, in order to hide prop trading from regulators. That gives the firm’s own traders more direct access to client information, and a greater ability to abuse it.

“A lot of people are caught up in a system that asks for morally dubious decision making,” says Smith. “I wrote the book about Goldman, but it’s really about the industry as a whole.”