I think this sort of ideal is more likely to reward than punish bad actors. I'm certain you can think of a million and one ways companies/PACs/individuals/etc could influence others in ways that would be difficult, if not impossible, to trace back to them. The player that tries to play by the rules and ensures that all of their messaging on the up and up is simply going to get burnt.

The wisest form of regulation is to assume bad actors from step 1 and try to create systems where the bad actors are encouraged to abide the rules, not out of threats, but because it benefits them in some way. For instance, the EU are aiming to force Netflix (and similar operations) to have 30% of their catalogue sourced from local productions... or else. It's not tough to predict the result. They'll license the premium stuff (which they probably already have) and then just stuff the rest with filler to hit the minimum.

Imagine if instead that Netflix and other companies received a tax deduction which was proportional to the percent of time their customers spent consuming locally sourced material. Now suddenly there is a positive incentive for the good behavior, and Netflix would almost certainly be going out of their way to try to get you to watch locally sourced material. On the other hand people often want to have their cake, and eat it too.