The Senate will question representatives of tech giants Twitter and Facebook on Wednesday. The chamber’s Intelligence Committee also invited Alphabet CEO Larry Page but rejected the company’s counteroffer to send Google’s chief legal officer.

Roll Call found 32 members of Congress have stock ownership in the three companies. These stocks are held in trust funds, IRAs and brokerage accounts for the members, their spouses or their dependent children. In total, members of Congress have invested more than $7,000,000 in the three tech companies subject to scrutiny in Wednesday’s hearings.

Of the three, Twitter finds itself especially in the committee’s crosshairs. The social media giant faces criticism for the way it allegedly filters political content on its platform. CEO Jack Dorsey is expected to face tough questions from panels in both the House and Senate for his company’s role in public space moving forward.

Rep. Michael McCaul has the biggest ownership in the tech companies, he listed more than $3.5 million Facebook and Google.

Only one of the members who will be questioning the tech leaders has any stock in the three companies. Maine Republican Susan Collins, who sits on the Senate Intelligence Committee, listed stock holdings in Google and Facebook, both worth more than $15,000. The Senate Intelligence panel will question Dorsey and Facebook COO Sheryl Sandberg in a hearing on foreign influence and the use of social media platforms.