Dirty tricks of debt collection: What you need to know

With more Americans than ever falling behind on their house, car and credit card payments, collection agents are turning up the heat and getting tough on debtors in an effort to recoup overdue funds.

"Some collection agents attacked my integrity," says Ken Golde (pictured), who was more than $200,000 in debt in 2007 after his business partner died unexpectedly. "They'd say, 'How can you look yourself in the mirror?' And one asked me, 'Do you have a wife? Do you have a girlfriend? What would your girlfriend think?'"

This sort of shaming happened often, says Golde: "One asked, 'Don't you feel just wrong about this?' Another asked, 'Don't you have any integrity?'"

As Golde unfortunately discovered, some bill collectors get rude and invasive. In some cases, they even cross line of legality. WalletPop spoke with lawyers and consumer advocates to find out what debt collectors can legally threaten you with -- and how to know when they've crossed the line.