Fashion store Urban Outfitters found itself in hot water this week when an independent jewelry designer accused the store of copying one of her necklace lines.

It wasn’t the first time the store, known for its hipster, urban fashion, has been labeled a copycat. In 2006, online vendor Johnny Cupcakes noticed that the store was selling a near replica of a T-shirt he had created showing a plane dropping cupcake bombs. In 2010, two vendors at the Brooklyn Flea market in New York found designs identical to their own on the store’s shelves.

But Wednesday was the first time Urban Outfitters has faced such a maelstrom of anger over a supposed imitation.

The controversy began Wednesday when independent Chicago-based jewelry designer Stevie Koerner published a post on her Tumblr blog. The post showed photos of her World/United States of Love line, which she has been selling for two years on e-commerce craft Web site, side by side with Urban Outfitter’s I Heart Destination necklace line. The similarities were impossible to miss.

Her post said that when she saw the Urban Outfitters line, “My heart sank a little bit. The . . . line that I created is one of the reasons that I was able to quit my full-time job. . . . I understand that they are a business, but it’s not cool to completely rip off an independent designer’s work.”

Twitter latched on to Koerner’s blog post, and soon so many users were rebuking the clothing store for the supposed imitation that “Urban Outfitters” became a trending topic on the social networking site in the United States, Canada and the United Kingdom. Twitter users called it a “PR Nightmare” and a “smackdown.”

Even pop singer Miley Cyrus got in on the debate, tweeting: “Not only do they steal from artists but every time you give them money you help finance a campaign against gay equality,” a reference to Urban Outfitters’ contribution of more than $13,000 to the presidential campaign of former Sen. Rick Santorum (R-Pa.), who opposes gay marriage.

Urban Outfitters responded with a tweet Thursday that said they were looking into the matter, but the company let its Twitter stream go silent Friday. Koerner said a representative of the store e-mailed her to tell her they would take the item down. The item’s link on the company’s Web site is now dead.

When an employee at the Urban Outfitters in Georgetown was asked about the jewelry line, he said, “Those aren’t available anymore. We can’t sell them at all because of what happened today.”

Urban Outfitters did not respond to multiple requests for comment.

John G. Froemming of Jones Day law firm in Washington, who has experience suing fashion imitators, says Koerning’s case is complex. He cited a case in which a person got a Mohawk in the shape of the New York skyline.

“That was not copyrightable, just like the shape of a state on the end of a necklace is not copyrightable. It’s about the modicum of creativity. But [Koerning] appears to have that because she stamped a heart design on the state,” he said. Urban Outfitters has the same heart stamp.

Nancy Prager, an intellectual property lawyer in Washington, doesn’t think Koerner would be able to sue. Prager was approached by a client in 2007 who wanted to sue Urban Outfitters for a graphic design product he created that he was sure the store had copied.

“It was close, but we could not prove it was a copy. In the fields of graphics and design, it’s very difficult to argue that it’s original,” Prager said. “Urban Outfitters is known for sending designers to craft events to get ideas. But that’s the key word: ideas.”

Whether Urban Outfitters is simply getting “ideas” or outright stealing, independent designers point out an irony of the whole fiasco — in 2007, Urban Outfitters accused fashion retailer Forever 21 of copyright infringement.

Koerner said she has no plans to sue. Since the controversy, the designer says she has been “overwhelmed” by the number of orders for the jewelry line and by the “love and support that has resulted from this incident.”