As Congress pushes for more details of the January 6th attack on the Capitol, tech companies have found themselves caught between a new request from the select committee investigating the attack and ominous threats from Republicans hoping to stall the committee’s investigation.

Pushing for new details about communications between Republican members of Congress and President Trump during the attack, the House select committee sent data requests on Monday ordering the preservation of phone records and other communications related to the January 6th attack. Requests went out to 35 companies, including Facebook, Twitter, Google, and Microsoft. Wireless providers like AT&T, T-Mobile, and Verizon Wireless also received the request.

Notably, the requests are likely to target some members of Congress who communicated with President Trump during the attack. Both House Minority Leader Rep. Kevin McCarthy (R-CA) and Rep. Jim Jordan (R-OH) reportedly discussed the attack with President Trump and could potentially be implicated by such a probe.

So far, Republican leaders have condemned the effort. In a statement Tuesday, McCarthy described the subpoenas as an effort “to strong-arm private companies to turn over individuals’ private data” and threatened retaliation from future administrations if the companies complied with the orders.

“If these companies comply with the Democrat order to turn over private information, they are in violation of federal law and subject to losing their ability to operate in the United States,” McCarthy wrote. “If companies still choose to violate federal law, a Republican majority will not forget.”

Speaking on Fox News that night, Rep. Marjorie Taylor Greene (R-GA) put the threat in blunter terms. “These telecommunication companies, if they go along with this, they will be shut down,” Greene said, “and that’s a promise.”

Thus far, the companies at the center of the fight are mostly saying quiet. Google affirmed its commitment to working with the committee but did not explicitly commit to serving the data request. “We have received the Select Committee’s letter and are committed to working with Congress on this,” a spokesperson said in a statement. “The events of January 6th were unprecedented and tragic, and Google and YouTube strongly condemn them.”

Reached by The Washington Post, Facebook gave a similar statement, saying, “We have received the request and look forward to continuing to work with the committee.”

Microsoft and Twitter declined to comment, while Verizon Wireless and AT&T did not respond to a request for comment.