Lobbying expenditures by other technology giants also increased as executives from Alphabet Inc.’s Google, Facebook Inc. and Twitter Inc. came to Washington to address allegations of political bias on their platforms from President Donald Trump and fellow Republicans and braced for the threat of more antitrust scrutiny.

Amazon (AMZN), which has boosted its federal lobbying far faster than rivals in recent years, spent $3.63 million on its efforts during the period, up from its previous quarterly record — set in the second quarter of this year — of $3.47 million, according to disclosures filed with Congress.

In addition to the Defense Department cloud contract, for which the company is thought to be the front-runner, Amazon also faced the tax implications of a U.S. Supreme Court ruling in June that opened the door for state and local governments to pursue sales taxes on more online transactions.

The online retail giant already takes in sales taxes in all states that charge them on transactions involving its own inventory, but about half of the items sold on Amazon come from millions of independent merchants who post inventory on the web store, and many of those sales have not been taxed.

Amazon disclosed lobbying on cloud computing in the context of homeland security as well as issues related to taxation of online sales, among other priorities. The company’s spending doesn’t represent an absolute record, as it reported higher expenditures in some periods when disclosures occurred twice yearly and weren’t broken out by quarter. Quarterly disclosures began in 2008.

In addition to Amazon’s spending, the Internet Association spent a group record of $800,000, up from $660,000 in the second quarter, which had been its previous top amount. The trade group counts Google, Facebook and Twitter as members.

Google (GOOGL) spent $5.46 million during the period, up more than 30% from the $4.17 million in the same period last year. In the three quarters before the current period, the search giant was the highest-spending single company, though some trade associations and other groups have spent more. So far this year, Google has spent almost 20% more than it had through the third quarter of 2017.

Facebook (FB) spent $2.82 million during the quarter, down slightly from $2.85 million a year earlier, while Twitter (TWTR) spent $310,000, a significant increase from the $120,000 it spent a year ago.

In September, Twitter Chief Executive Officer Jack Dorsey and Facebook Chief Operating Officer Sheryl Sandberg testified before Congress. They addressed online foreign influence campaigns in U.S. elections and attempted to swat down charges that their platforms silence conservative voices and news.

In August, Trump had also warned Google, Facebook and Twitter that they “better be careful” as he repeated unsubstantiated allegations the companies favor liberal views. The companies have said they do not silence people for their opinions, though they have acknowledged mistaken enforcement actions that affected conservatives.

Facebook lobbied on “content and platform transparency efforts” and “freedom of expression on the internet,” among a variety of other issues. Twitter lobbied on “issues related to content moderation practices” and “misinformation,” along with other topics, according to the filings.

Tech companies have also been facing increased scrutiny over their size and market power, including consideration by the White House of an executive order that would instruct federal antitrust and law enforcement agencies to open inquiries into the practices of Google and social media companies. Amazon has also been the subject of criticisms of its competitive position. The companies reject the claims.

The Internet Association trade group was also one of several companies and business groups that released principles for a federal privacy law during the period. Congress is looking to legislate in the area.

The Information Technology Industry Council, another tech trade group that issued its own privacy principles on Monday, spent $450,000 during the quarter.

No. 1 software maker Microsoft Corp. (MSFT) spent $2.24 million, Oracle Corp. (ORCL) spent $1.44 million, and International Business Machines Corp. (IBM) spent $900,000. All three have also bid for the Defense Department’s cloud contract.

Among telecommunications providers, AT&T Inc. (T) spent $3.85 million, Comcast Corp. (CMCSA) spent $3.43 million, Charter Communications Inc. (CHTR) spent $2.27 million and Verizon Communications Inc. (VZ) spent just over $2.33 million.