LEADING THE DAY: AT&T disclosed that it has spent $6.84 million on lobbying in the first quarter, up from $5.93 million by the same time last year, the Associated Press reported. The company spent its lobbying dollars on a variety of issues, including patent reform, cellphone taxes and health-care reform. Congress, the NTIA and office of the vice president were all lobbied by the company.

Report says LightSquared interferes with GPS: LightSquared and GPS industry reports indicate that the company’s planned satellite-based mobile broadband network will interfere with GPS receivers, The Washington Post reported.

LightSquared, which is based in Reston, simultaneously filed a plan that it says will resolve the issues, but members of the GPS industry said the company’s plan will not work.

“There is no existing technology that solves this interference, only unproven claims of hypothetical future fixes,” Jim Kirkland, vice president of GPS firm Trimble, told The Washington Post.

FTC asks questions about Twitter: The Federal Trade Commission has asked UberMedia, a group that makes third-party applications for Twitter, for more information about the micro-blogging company, The Washington Post reported. Twitter has been exerting more control over its developer ecosystem and has acquired several companies to incorporate more features into its main product.

UberMedia, run by Silicon Valley entrepreneur Bill Gross, confirmed that the FTC had contacted it about Twitter but declined to give any more details about the request.

Comcast exec raises $1.2 million for Obama: Comcast executive vice president David Cohen raised at least $1.2 million for President Obama’s reelection campaign, The Washington Post reported. Cohen hosted a 120-person dinner in his home, with each of the attendees giving at least $10,000. Cohen, a longtime Democratic supporter, successfully shepherded the regulatory review of Comcast’s merger with NBC Universal this year.

Obama has received previous support from tech executives including Salesforce.com CEO Mark Benioff and Google executive Marissa Mayer.

Groups urge action on privacy laws: A coalition of privacy advocates including the American Civil Liberties Union and the Consumers Union will send a letter to the Senate Commerce Committee on Friday, urging Sens. Jay Rockefeller (D-W.Va.) and Kay Bailey Hutchinson (R-Tex.) to act quickly on privacy legislation, saying there is mounting evidence that current privacy practices aren’t working.

The letter is in response to one sent this week from groups including the American Advertising Federation and the U.S. Chamber of Commerce saying that industry self-regulation is the best way to address privacy matters.

Verizon/Android tethering: Professor Barbara van Schewick of Stanford University has asked the FCC to let the public comment on a proceeding regarding the practice of tethering, or sharing a mobile phone’s broadband connection with multiple devices. Verizon Wireless recently asked Google to disable Android Market apps that allow the practice. This month, Free Press filed a complaint with the FCC, claiming this action violates Verizon’s spectrum license for the LTE network, which dictates that the company can’t “deny, limit or restrict” customers’ choices of applications.

Van Schewick sent a letter to FCC Chairman Julius Genachowski asking him to open up the debate, which she said has important implications for Internet openness. She said AT&T and T-Mobile have also asked Google to disable similar apps.