Senator Elizabeth Warren (D-Mass.) continues to hit out at presumptive GOP nominee Donald Trump’s business practices.The most obvious deception of Trump University stares you right in the face: The now-presumptive Republican nominee’s for-profit education company, which offered real estate seminars, was not an accredited academic institution.

There were other alleged scams, of course ― internal documents unsealed by a court order told employees to emotionally manipulate people into buying classes and, according to court testimony, employees even pressured customers to max out their credit cards ― accusations which Donald Trump’s lawyers and campaign deny.

A Trump campaign spokeswoman said Trump will win a jury trial. But whether the allegations of former students now suing Trump University are true, it’s unlikely the company would have attracted as many customers without Trump’s brand name and its “university” tag.

Now, Sen. Elizabeth Warren (D-Mass.) and 11 other progressive senators want regulators to warn consumers about businesses posing as colleges or universities without proper certification.

The senators wrote a letter to the Consumer Financial Protection Bureau, the Department of Veterans Affairs, the Education Department and the Federal Trade Commission asking the agencies to set up an online alert system that warns people about for-profit education scams before they get roped in.

Regulators should “take immediate steps to warn consumers regarding unlicensed and potentially fraudulent universities,” the letter says.

The lawmakers are also urging regulators to enforce existing laws to protect consumers. Their letter points out that in 2005, New York regulators told Trump University that the company was violating state law because it was not a chartered university. Nonetheless, the senators say, it took five years to get the company to stop marketing itself as a university.

The senators are asking for a response by August 31.

Read their letter below.