Ever see national banks with a table set up around campus? That is because they are specifically targeting college students and now the U.S. Consumer Financial Protection Bureau is investigating, ABC News reported.

The consumer watchdog agency is among critics who believe the banks lure college students into opening checking accounts that have hidden fees. The investigation is looking specifically at the deals in place between the banks and the universities.

"Unfortunately, many see students as nothing more than dollar signs in backpacks," said Rohit Chopra, an investigator in the case. "Too often these deals aren't what's in the best interest of students."

According to a Public Interest Research Group study last year, more than 900 universities have agreements with banks, meaning those banks could be reaching as many as nine million students.

Also in on the investigation are members of Congress. Students and parents are often not made aware that the school has allowed certain banks to have exclusive access to campus. While some banks are just setting up a table and giving away t-shirts for opening an account, some banks have struck deals to turn student ID cards in to ATM cards.

"[Schools are] looking to make up revenues in creative ways," Chopra said. "And one of those creative ways is marketing arrangements with financial institutions."

According to documents obtained by ABC News, TCF Bank, a Minneapolis-based bank, and the University of Minnesota (UM) have a multi-million dollar deal in place that pays the school about a million dollars per year.

TCF Bank has a branch on campus and some of its employees are university staff. The bank encourages students to make their ID cards double as TCF debit cards and open a "no fee" checking account that is "virtually free." Students who do so and deposit $50 are given a free UM Gophers sweatshirt. But, for every account opened, the school gets an addition $34 on the initial deal.

School officials assured ABC News that students are welcome to look elsewhere for banking, but U.S. Rep. George Miller, the ranking Democrat on the House Education Committee, said that is not quite the case.

"What we see here is that they've shopped for the best deal for the university, not for their students," he said, adding that 85 percent of incoming UM freshman sign up for TCF Bank accounts.

"People have an attachment to their university," Miller said. "And the university is using that to persuade these students to engage in this practice whether or not it's to the benefit of the students."

For example, the TCF Bank checking account charges its holder $37 for every time they swipe their debit card for a transaction in which they do not have the funds. 21-year-old Mike Schmidt, UM student body president, said he knows someone who was stung by this charge "four or five times" in a day while buying books. Some national banks offer a grace period for spending too much, allowing an account holder to deposit the money over-drawn by the end of the day with no penalty.

Jason Korstange, the director of corporate communications for TCF Financial Corporation, said this is not an issue with UM students.

"Our student account holders overdraft less than twice a year, not twice a month," Korstange said. "The overwhelming majority don't overdraft at all."

UM released a statement to ABC News, but did not comment on their contract with TCF Bank.

"The University of Minnesota shares the concern of ABC News and policymakers that there may be existing questionable practices by some financial institutions that adversely affect students," the statement said. "In such cases, the University supports policymakers who want to do what's best for students. We share that goal and our contracts and policies reflect these values. While there may be some existing business arrangements across the country that negatively affect students, the U of M's relationship with TCF Bank is not one of them."