Should there be limits on interest group participation?

What a topic to undertake, whew... Okay, here goes. I think that the government should regulate political interest groups. While I don't think the government has the right to say what issues are more important than others or what lobbyists should get the most face time, I do think it would be a legitimate and good idea to disclose Interest Group finances. As a citizen who may or may not be a part of an interest group, I want to know where these people are getting their money and whom is financing them. Interest groups have a massive influence on society, therefore I think finances should be disclosed. I'm not saying that Interest Groups should have to pass ridiculous tests and limits saying what they can and can't say or who's allowed to do this or that, I'm merely saying make the finances public record. JUST the finances...not the agenda. For example, what business does George Soros have in donating $15.8 million to MoveOn.org. After a little research via wikipedia, I found out how much he dislikes George Bush...he's a democrat to the max so it makes sense for him to want to fund MoveOn.org. While there's no underlying sneaky agenda to his funding, I would want to know if there was--publish the paper trail. That's all I'm saying.