Updated: Jan. 23, 8:40 a.m. | It may have been a do-little Congress, but lobbyists of all stripes made their presence felt on Capitol Hill this past year.

Business groups and defense firms pounded the marble floors to beat back automatic spending cuts under the sequester and keep their favorite tax benefits out of deficit negotiations. The U.S. Chamber of Commerce was poised to retain its perch as the top-spending interest group, investing almost $104 million in 2012, according to lobbying disclosure reports due Tuesday.

Meanwhile, Internet firms staked out new territory, deploying an army of young lobbyists to fight online piracy legislation and shape cybersecurity policy. And with cuts to entitlements and potential tax changes on the horizon, corporate lobbyists and advocacy groups are likely to be even busier this year.

Here are some of the costliest and most notable lobbying efforts:

Big Business Fights Fiscal Cliff

The fiscal-cliff standoff kept the big-business lobbyists busy. Two of the most prominent groups, the chamber and the Business Roundtable, posted an uptick in their lobby spending in 2012, according to the filings.

The chamber reported spending $103.9 million on lobbying and issue advocacy in 2012, up dramatically from the $44.2 million it reported in 2011.

A chamber spokeswoman explained in an email that the organization files its lobbying reports under a method that conforms to IRS standards and includes issue and voter advertising. The Lobbying Disclosure Act, which mandates quarterly reporting, doesn’t cover those categories of spending.

“It was an election year where the chamber engaged in an unprecedented voter education campaign to educate the public about candidates’ positions on issues critical to free enterprise, such as health care, regulation, energy production and taxes,” spokeswoman Blair Latoff Holmes said.

The sum didn’t come close to the record $157 million the chamber spent in 2010.

The Business Roundtable, whose CEO members made regular visits to Washington in December for meetings on the fiscal cliff, reported spending $13.9 million on lobbying last year. That was up slightly from 2011, when it spent $12.3 million.

The fiscal drama wasn’t the only agenda item. The chamber, for example, filed a 59-page report detailing its work in the fourth quarter. Its issues included implementation of the Dodd-Frank financial law, the defense authorization bill and online gambling and poker legislation.

Internet Firms Increase Footprint

Google Inc.’s 2012 expenditures could land it among the top 10 lobbying forces in Washington, edging out longtime heavyweights such as Boeing Co. and the American Medical Association.

With more than 10 in-house lobbyists and almost two dozen outside firms on contract, the company spent more than $18 million lobbying in 2012, nearly double its 2011 tab. In the final three months 2012, however, the Internet search giant only spent $3.35 million, the least it spent in any single quarter last year. The overall increase is likely related to a series of federal investigations into potentially anti-competitive practices at the search engine company.

The online gaming company Zynga, which signed its first two Washington firms this summer, continues to increase its spending, reporting $80,000 in fourth quarter of 2012. While Facebook rounded out the year with just under $4 million in lobbying expenditures.

The Google number is striking given the company and its leadership’s ties to the Obama administration. Chairman Eric Schmidt, a major Democratic donor, will serve on the board of Organizing for Action, the new nonprofit made up of President Barack Obama’s army of grass-roots campaign supporters. Google has also become a fixture at national party conventions and the inauguration. On Sunday, the company partnered with the Center for American Progress to fete female members of Congress.

The Internet Association, a new trade group launched earlier this year to represent Google, eBay, Amazon and other Internet interests, just registered its first two lobbyists, Michael Beckerman and Gina Woodworth. The group reported no spending in 2012.

Gun Policy Battles

In the aftermath of the massacre at a Connecticut elementary school, National Rifle Association lobbyists suspended activity, swinging into action only in the final weeks of the year.

The $2.5 million the NRA spent in 2012 represented a slight drop from 2011, but the group still flexed major muscle during the campaign season, investing almost $19 million in congressional races.

As the first legislative responses to Obama’s sweeping gun control proposals emerge, there is little doubt the NRA and its opponents, including Mayors Against Illegal Guns, will increase their lobbying activity.

Stop the Sequester

The threat of automatic defense cuts known as the sequester, which Congress delayed in December, explain why the Aerospace Industries Association spent record levels on lobbying this past year.

The AIA reported $2.9 million for 2012, up from $2.2 million in 2011. Both years represented a dramatic uptick in the group’s previous lobbying filings, which as recently as 2010 did not break $1 million.

The AIA has taken a leading role in urging Congress to come up with alternatives to the sequester. Part of that effort is the AIA-run “Second to None” campaign, group spokesman Dan Stohr said.

“My personal lobbying reports went from almost zero to almost half of my time,” Stohr said. Stohr is not a registered lobbyist, however, because he does not have meetings with covered government officials. Instead, he focuses on messaging and media relations.

The National Association of Manufacturers, which has issued grim reports estimating the effects of the sequester, reported an uptick in K Street spending from $8.2 million in 2011 to $9.2 million in 2012.

The looming cuts, which still could materialize this year, didn’t persuade every defense player to boost lobbying. Lockheed Martin Corp. reported spending $5.2 million for both 2012 and 2011. And General Dynamics Corp. reported a decline in lobby spending, $11.4 million in 2011 to $10.8 million last year. Ditto for United Technologies Corp., which last year reported $13.1 million, down from 2011’s $14.3 million.