Last week, as Wicker had been pushing internally for the subpoenas, Cantwell said she feared Republicans sought to "chill the efforts of these companies to remove lies, harassment, and intimidation from their platforms."
Lawmakers have introduced a series of bills designed to scale back the law's protections and create greater legal exposure for tech companies.
Under Section 230, websites and tech platforms cannot be held liable for the content their users create, and companies are given wide freedom to moderate their sites as they see fit.
The subpoenas aim to force Mark Zuckerberg, Sundar Pichai and Jack Dorsey to testify about the legal immunity the law affords tech platforms under Section 230 of the Communications Act of 1934 .
On Thursday, Cantwell said she was pleased to move forward with the subpoenas after Wicker agreed to include the topics of Big Tech's impact on media and privacy as issues of concern.