Hey Gank. Actually, when you're a platform, you're saying you take no responsibility for the content on your site. When you start to edit that information, you become a publisher. These 2 roles have very different legal meanings. With regard to private companies refusing service, you can't refuse service to anyone based on political, racial or economic discrimination...even as a private business. You can outline rules that must be followed, but those rules also can NOT be discriminatory in nature.
The problem with these sites, they're editing political content they don't like. CLEARLY this proves they aren't platforms in the legal since. This makes them a media outlet, responsible for the content on their site...yet they claim they aren't media outlets.
Now I agree with what many have said, the wording of current laws has not yet caught up to technology...and it needs to. But the fact still remains, these sites are claiming "platform" status, while editing the content on their sites by purging political opinions they disagree with. They're trying to hide behind user rules being broken. When asked what rules were broken, 99% of the time they say, "oh, our mistake, it's the algorithm's fault". Funny how that algorithm always only deletes one side of a political argument.
Look, if they had a defined standard that was not discriminatory in nature, that would be one thing. But they don't. Instead they keep the standard vague so they can always blame the mysterious algorithm. If the standard was to ban any hate filled person, then countless people like Al Sharpton would be banned. But they don't ban them because there is no objective standard they're using. Instead they cherry pick certain people, point out something they did off the site, and then say it breaks the current rules on the site. That's an impossible standard. It allows discrimination of nearly anyone they want, while giving a pass to others. You could say that's within the rights of a private business, but again, that's NOT true when discriminating against political view points...which is clearly what's happening.
If they would just admit they're acting as a media outlet, then they're free to allow certain political views, while suppressing others...but that's NOT what they're claiming. They want all the benefits of a media outlet, with none of the responsibility of a media outlet label.
By the way...I'm afraid you're mistaken on Twitter? Their CEO, Jack Dorsey, is as far left as they come. He's admitted the company wrongly targeted conservatives.