HBO
Credit-reporting companies - the biggest of which are Transunion, Experian, and Equifax - and the scores they crunch for individuals are obviously important, especially considering how they're used.
"It's not just banks deciding whether to lend you money," Oliver said. "It's also landlords deciding whether to rent you an apartment, insurers setting your rates, and even employers using it to decide whether or not to hire you."
That's especially problematic considering just how plagued with errors credit reports can be. Oliver pointed out a 2013 FTC study showing that 25% of credit reports had errors and that 5% had serious enough errors to affect one's ability to take out loans.
These mistakes can be as small as reporting errors from credit card companies or as big as mistaken identity, being falsely labeled a terrorist or a sexual offender, and even being declared dead when you're alive.
"Just one error on your credit report, and suddenly the world treats you like a mean girl treats the high school debate team," Oliver said, before imitating a teen girl saying, "You're nothing, Amberly. You don't even exist."
Meanwhile, credit reporting agencies would rather draw attention to the 95% of reports that don't have serious errors. In response, Oliver decided to provide some perspective.
"When you are holding records for more than 200 million individuals, that 5% error rate affects 10 million people," Oliver said. "They're basically saying, 'Great news, everyone: We only f---ed up a group equivalent to the entire population of Sweden!'"
Oliver decided to cook up a way to show the agencies just how terrible errors can be.
"We started three terrible companies with names that are problematically similar to theirs," he explained. "Specifically, Equifacks, Experianne, and TramsOnion."
Watch Oliver's take on credit reports below: