More cards, more chances for fraud
When you have too many cards, you become that much more of a target for someone to try to steal your identity or commit fraud with your money.
Harzog says that people should check all of their accounts frequently -- once a day to once a week -- to make sure there are no fraudulent charges. That task becomes more daunting the more accounts you have.
The environment is getting even riskier because hackers are getting more tech-savvy about stealing people's information, McClary says.
That's why people should try to minimize how many different places have their information, including credit card companies big and small.
"The more accounts you have the better the odds are that one of those accounts might end up getting compromised," McClary says. "An unused account sitting for too long, especially if it is sitting unmonitored, is easy prey for identity theft or credit card fraud."
And if fraud does happen to an account where you aren't paying attention, you may not catch it in time to recuperate the lost money.
More credit, more spending?
With all of the cards he's opened, Cavanagh has lined up an impress $1.7 million credit line, but that doesn't mean he should go on a shopping spree he can't afford to pay off. (And, to his credit, Cavanagh reportedly only uses one of those cards and pays it off monthly.)
Opening credit for the sake of being able to spend outside your means is never a good idea, experts say.
Not only will you wind up in trouble when the bills come due and interest charges start racking up, but your credit score will take a hit, too. Check your credit score for free now with myBankrate.
FICO keeps track your credit-utilization ratio -- or how much of your available credit you've used. "The ratio goes up, your score goes down," Harzog says.
Maxing out every credit card you have open will bring down your credit score, Harzog says, which could hurt your ability to buy a home, car or make other big purchases for years to come.
Not all bad news
Credit doesn't have to be an all or nothing situation, though. Just because it's not a good idea to have more credit cards than days in the year, doesn't mean opening a new card is never a good idea.
Just make sure to shop competitively, read the fine print and make sure you can handle the payments. Ready to get a new credit card now? Let Bankrate.com help you choose the right card for you.
"It's easy for people to apply for more credit than they can handle or be enticed by the offers," McClary says. "But people need to curb their appetite for credit and manage the debt they already have."