I thought about something similar, but more generic, as a public relations countermeasure. Some time ago I read an article on a website, about freedom of consumers. And then another. I agreed with both. The next one was claiming that it is good for me as a consumer to NOT know the food content. That made me wary and I looked up the website's background - and it was sponsored by a fast food coalition! And an idea was born, and I am sadly too incompetent to properly implement it yet.
It would be good to have something that would allow quick identification of such astroturf groups.
A good source for such information is SourceWatch. I think they could be talked into providing data feed for such plugin.
...as of politicos, a fun thing for video would be something that'd identify them and then add the sponsor logos on their clothes, so they'd look like NASCAR drivers...