How have factions, interest groups and lobbies been regulated?

There are various regulations at the state and federal levels. Read about it:

http://www.google.com/search?sourceid=navclient&aq=&oq=regulations+for+lobbyists&ie=UTF-8&rlz=1T4VRHB_enUS648US649&q=regulations+for+lobbyists&gs_l=hp....0.0.6.1570135...........0.5xB-c5PEm14