The Federal Regulation of Lobbying Act of 1946

Provisions
Section 308 "(a) Any person who shall engage himself for pay or for any consideration for the purpose of attempting to influence the passage or defeat of any legislation by the Congress of the United States shall, before doing anything in furtherance of such object, register with the Clerk of the House of Representatives and the Secretary of the Senate and shall give to those officers in writing and under oath, his name and business address, the name and address of the person by whom he is employed, and in whose interest he appears or works, the duration of such employment, how much he is paid and is to receive, by whom he is paid or is to be paid, how much he is to be paid for expenses, and what expenses are to be included . . . "

Section 307 describes who it applies to: "The Provisions of this act apply to any person (except a political committee as defined in the Federal Corrupt Practices Act, and duly organized State or local committees of a political party), who by himself, or through any agent or employee or other persons in any manner whatsoever, directly or indirectly, solicits, collects, or receives money or any other thing of value to be used principally to aid, or which the principal purpose of which person is to aid, in the accomplishment of any of the following purposes:
 * The passage or defeat of any legislation by the Congress of the United States.
 * To influence, directly or indirectly, the passage or defeat of any legislation by the Congress of the United States."

United States v Harriss
In 1953, The Supreme Court Upheld the Federal Regulation of Lobbying Act, but narrowed its scope significantly. The Court determined that it applied only to paid lobbyists who directly communicated with members of Congress on pending legislation. This created a number of loopholes including:
 * It does not regulate people who give money to influence legislation, only those who solicit or collect money
 * It does not define "principally." A lobbyist can argue that his principal goal is not influencing legislation
 * It does not include those who communicate with Congressional Staffers