We Americans love our celebrities. We even elected one of them President of the United States. But where do love and admiration end and "celebrity worship" begin?

"People use celebrities as a form of escapism. We all do this," said psychologist James Houran, who specializes in pop culture. "But at slightly higher levels of celebrity worship, it stops being voluntary."

Rumeal Robinson, who led the University of Michigan to its first NCAA basketball championship in 1989 and went on to play five seasons in the NBA, knew he has his share of worshipers. As told on the latest episode of CNBC's "American Greed," Robinson milked his status for all it was worth. He served five years in prison following his 2011 conviction on eleven felony counts in a loan scam that took in some of his biggest fans.

Chief among them was the loan officer Robinson convinced to help him finance a purported mega-resort in Jamaica. The officer spoke to "American Greed" on the condition that his name be withheld.

"I think I was a lot star struck at first," he said. "When somebody has made it to the level he made it, and I had aspirations to get there myself at one point in time. But I gave it more credibility than I should have."

The bank official helped Robinson secure a $377,000 loan in exchange for a $100,000 kickback. More loans followed. In the end, Robinson managed to scam some $700,000. The money went not toward a resort development in Jamaica, but to his own lifestyle.

"I had the opportunity to switch on the light and tell everybody, 'Hey, there's probably something wrong with this,'" the loan officer said.

Instead, celebrity worship took over.

If your favorite celebrity asked you to do something illegal, would you do it?

Before you answer that question, consider the fact that according to Houran, as much as one-third of the general population is at what he calls "stage two" of celebrity worship.

"In other words," Houran said, "They feel an intense, personal connection to a celebrity at the expense of their real relationships. Or they have that plus they're willing to act on it."

Compounding the problem is the changing nature of celebrity. Now more than ever, people are famous just for being famous.

"These people are constantly vying for attention from the media and from fans. And they'll do whatever it takes to get that attention," Houran said. "And sometimes, they may be a little lax themselves in how their marketing and personas are being used."

To protect yourself, Houran says you should condition yourself to never take things at face value—coming from a celebrity or anyone else.

"We are only falling prey to a marketing product, and we should be wise enough to listen to what our family and friends say about circumstances, and take their advice versus the advice of someone that we don't even know," he said.

Besides, even if your favorite celebrity's name and face are on the sales pitch, that does not mean he or she is involved at all.

The U.S. Federal Trade Commission warns about scams that make unauthorized use of celebrity names to endorse a product. Just this month, the agency obtained a consent judgment involving four defendants accused of improperly using the names of Oprah Winfrey and the stars of the syndicated program "The Doctors" to promote weight-loss products.

The FTC offers these tips on spotting fake celebrity endorsements:

• Don't click emailed links or open attachments, even if you think you know the sender. Emails that seem to be from a friend might not be.
• Intrigued by weight-loss claims? Anyone saying they lost more than a pound a week without diet and exercise is probably lying.
• Learn how to spot a fake news site, which often include fake celebrity endorsements. These actually are elaborate ads created by marketers.
• File a complaint with the FTC if you ever spot a scam, or get sold on phony product promises.

"We really should, if anything, be more cautious whenever we see a situation that a celebrity is telling us about and encouraging us to take part in," Houran said.

That piece of advice might have kept Rumeal Robinson's scam on the sidelines.

See how Rumeal Robinson even managed to scam his own mother in the next all-new "American Greed" — Monday, March 20 at 10P ET/PT only on CNBC.