The new movie “Identity Thief” sees comedian Melissa McCarthy playing crime for yuks, but it’s also giving those who know the serious side of ID theft a chance to nudge viewers in the ribs.

Firms that collect credit data are ready for calls from reporters.

“ID theft is a big and growing problem,” said Trey Loughran, president of personal information solutions at Equifax.

ID fraud was up 13 percent in the U.S. from 2010 to 2011, Loughran said. The 2012 numbers are not compiled yet, but he expects to see another jump.

Experts say the proliferation of information online and in customer databases such as those kept by online retailers is adding to the growth.

Tax return fraud is one of the quicker growing crimes, he said.

The inspector general of the Internal Revenue Service estimated last July that the government could send as much as $21 billion in the next five years to fraudsters who have used others’ identities to file for tax refunds.

Steve Fennessy, the editor of Atlanta Magazine, knows firsthand about ID theft. He has written about the Florida man who snatched his identity more than 10 years ago.

One result is that Fennessy still keeps a letter in his glove box from Florida law enforcement officials in case he gets pulled over by a policeman. The letter says he should not be confused with Brian Katacinski, the scammer who used Fennessy’s name on a fake driver’s license. Katacinski is in federal prison for snatching and abusing multiple people’s identities, but his crimes can still haunt Fennessy because Fennessy’s name is now one of Katacinski’s aliases.

“I get associated with him,” Fennessy said.

“Once you are in the (law enforcement) computer database,” he said, “it is a wormhole you can’t get out of.”

Loughran said consumers should protect their Social Security numbers and be ready to question why anyone would need that.