In a letter to Intuit CEO Sasan Goodarzi, Warren, as well as Reps. Katie Porter and Brad Sherman, laid into the company over its TurboTax tax-filing program's fees. 

At the core of their concern is the IRS' Free File program, through which TurboTax and other participants were supposed to offer tax preparation services to low-income Americans for free. 

Warren, Porter and Sherman hold TurboTax partly accountable for that, in light of reporting by ProPublica 

They argued Intuit's "influence peddling" in Washington has allowed these issues to fly under the radar. The company previously hired a former top IRS official to be its chief tax officer 

Now, Warren, Porter and Sherman are asking Intuit to answer questions about its "revolving door" with the IRS and other government agencies.