That sounds like a great thing to raise as an issue in an election. Lots of voters might care about that. However, we have a First Amendment, so it's not against the law for anyone to talk to anyone else. That's the case whether it's some weird social media thing like those pictures of Bernie with big muscles or an actual true fact like that the DNC staff sent emails to each other discussing how they had screwed over Bernie. That is strictly legal, whether it is done by Russians or by the Citizens United dudes or by the actual Wikipedia source.