New York ? Goldman Sachs, arguably the most storied investment bank on Wall Street, has been compared to a money-sucking vampire squid and called the evil empire of finance. On Wednesday, it got a black eye from one of its own.

Greg Smith, an executive director at the bank, resigned with a blistering public essay that accused the bank of losing its “moral fiber,” putting profits ahead of customers’ interests and dismissing customers as “muppets.”

“It makes me ill how callously people talk about ripping their clients off,” he wrote.

The decay of Goldman’s proud culture of teamwork, integrity and humility, he wrote, threatened the survival of an investment house that weathered two world wars and the Great Depression.

The stinging essay, “Why I Am Leaving Goldman Sachs,” appeared on the Op-Ed page of The New York Times on Wednesday morning. It was the talk of Wall Street immediately and circulated online all day.

CNBC ran clips of the ornery balcony critics from “The Muppet Show.” Other websites quickly posted spoofs, including “Why I am Leaving the Empire,” by “Star Wars” villain Darth Vader. Smith became a trending topic on Twitter.

The Times said the essay had received 3 million page views online by 4 p.m. The second-most-viewed story had 500,000, and that was a business section story about the essay.

Goldman CEO Lloyd Blankfein and President Gary Cohn told the bank’s employees in an open letter that Smith’s claims did not reflect the culture of the bank. They cited glowing internal reviews of the service Goldman provides to clients.

“It is unfortunate that all of you who worked so hard through a difficult environment over the last few years now have to respond to this,” they wrote.

Smith worked for Goldman in London when he resigned, but the bank did not provide further details or say how much money Smith made. He previously worked in the New York office.