Big corporations use a variety of techniques to manipulate public policies. The standard tactics that receive the most publicity are lobbying, campaign contributions and (supposedly) independent campaign spending, and the revolving door between jobs in corporations and related jobs in the public sector, including as regulators of the industry where the person formerly worked.
Less recognized and publicized techniques for affecting policy include funding think tanks and (supposedly) independent research and academic publications. Corporations also have funded (supposedly) grassroots organizations to advance their interests. Probably the most famous (or infamous) one is the National Rifle Association (NRA). Although it is a membership organization and is viewed and presented as a grassroots organization, it is heavily funded and supported by the manufacturers of guns and ammunition. It is what is called an “astroturf” organization, i.e., fake grass(roots).
Another tactic that is being adopted by the Big Tech corporations has more traditionally been associated with the military and the defense industry: putting jobs in the districts of key and powerful legislators. The military has for decades worked to have bases, other facilities, and contractors in every state and congressional district. The defense industry corporations have worked to spread their facilities and jobs widely across the country. This meant that when cuts to defense spending, such as closing of some bases, was discussed or when cutting funding for a specific weapon system was raised, it meant that congressional representatives considering voting to cut spending were painted as cutting jobs, often in their own districts. That’s a tough vote to make!
Recently, the four Big Tech corporations, Amazon, Apple, Facebook, and Google, all appear to have adopted this job placement strategy. In late 2017, Rep. Jerry Nadler of New York City became the ranking minority member of the House Judiciary Committee and became its chair when the Democrats won control of the House in the 2018 elections. The House Judiciary Committee is currently investigating the four Big Tech corporations for antitrust violations and anti-competitive behavior.
All four of the Big Tech corporations have announced they are opening offices and bringing jobs to the section of Manhattan which just happens to be in Judiciary Committee chair Jerry Nadler’s district. Amazon has recently signed a lease for space that will house over 1,500 employees. Not only does this put these jobs in Nadler’s district, but if the employees happen to live nearby, they will be voters in his district as well. (Remember that Amazon only months earlier had pulled out of a deal to locate its second headquarters in nearby Queens, despite having been promised (extorted?) $3 billion in public subsidies to locate a promised 25,000 jobs there.) 
Apple, Facebook, and Google have either opened new offices in New York City or announced plans to do so. All of them are on the west side of Manhattan in Nadler’s district. There is plenty of real estate elsewhere in the New York City area, so the fact that all four Big Tech firms happen to be locating in Nadler’s district is more than a little suspicious. (By the way, the runner-up for the position Nadler got on the Judiciary Committee was Rep. Zoe Lofgren, whose district includes a chunk of Silicon Valley.)
It is projected that by 2022 the four Big Tech corporations will have over 20,000 employees (and potentially voters) in nine different locations all on the west side of Manhattan in Nadler’s district.
The Judiciary Committee’s investigations, under Chairman Nadler, are the most significant antitrust investigations in decades and their outcomes could have significant effects on how the Big Tech corporations conduct their businesses and on their profits. Placing jobs in Nadler’s district, with the implicit or potential threat that those jobs might be at risk if Nadler and the Judiciary Committee take action that is viewed unfavorably by the Big Tech firms, is an escalation of these corporations’ on-going and persistent efforts to manipulate public policies in their favor. 
 Dayen, D., 1/10/20, “Silicon Valley’s big apple gambit,” The American Prospect (https://prospect.org/power/silicon-valleys-big-apple-gambit/)
 Dayen, D., 1/10/20, see above