If they're smart, they'll self-police before it becomes a question of legal remedies.
Whether or not it was the case, there should not be any question whether the elections of the world's supposed shining example of democracy might have been decided based on a foreign mafia state's disinformation campaign. Any companies that may have been unwitting accomplices need to own up and begin working on defensive measures immediately.
This isn't just an abstract game of geopolitics, they're literally trying to incite racial violence.
1: http://thehill.com/policy/technology/353480-report-russian-b...
2: https://www.recode.net/2017/10/7/16439936/congressional-blac...
3: https://thinkprogress.org/armed-white-supremacist-protest-or...
at some point human beings have to take responsibility for their own decisions instead of blaming everyone else.
The way I see it, ads work, but I feel the Russian angle is mostly overblown bullshit, and US with its history of fucking up elections worldwide should be the last to point fingers.
That said, I'd love for people to be consistent. If one believes that Russian targeted ads were so influencial that they swayed the election, they should just admit that ads are that powerful, and follow it to the natural conclusion - that the advertisement industry is evil and malicious, a disrespectable profession that's an affront to a free society. It's just people taking advantage of other people. So let's talk about that, and not about Russians.