I agree that this is aimed at astroturfing, but I don't think it'll work that way.

I think that it's intended to stop corporations and political organizations/parties from faking a grass roots movement by making it explicit who is supporting their views (i.e. is it their own view or their client's view?).

If I have a blog and corporation X pays me to 1) complain about legislation that X is unhappy with, 2) exhort my readers to contact his congressman, and 3) not mention that X paid me to do any of the forgoing, then I'm engaged what I think the bill is looking to curb.

But I think there'll be too much grey area for all that to work unless the bill/law turns out to be as orwellian as has been suggested by some in here.

For example, what if I receive funding from X, complain about the legislation, but never ask anyone to contact congress about it?

What if I had previously never been paid, but had been complaining about the legislation anyway when X makes a donation, but X never actually instructs me to goad the public?

What if I am a founding member of an organization of people and companies that X belongs to and which share X's views? Does this change whether or not X pays dues?

What if X instead of paying directly for the message instead pays indirectly by buying advertising?

I really dislike astroturfing, operations, but I cannot see how this law will get around it without infringing on First Amendment rights in its most important application: political speech.