About Facebook and social media in general: I'm not planning to leave it any time soon, it's a good and valuable way to stay in touch with friends and the community, follow and contribute to causes.
But I agree that regulation has to come and in the light of the recent events there's certain urgency to it. The main problem is, these platforms cannot be taken, claimed and used as a free, unlimited and out of any control means and channels of spreading false information for monetary benefits/profit to the owners. That was never their declared purpose it is misleading users and it has to stop or be stopped.
This is not a small matter. As researchers working with information and learning systems we come to understand that learning systems, regardless of their nature, natural or artificial, create models of the environment based on the sensory feeds, samples they observe in interactions with it. Getting distorted and even corrupted feeds can and will result in distorted models of perception, decision and behavior. There's a direct logical connection between the sample learner gets, and development of their interpretation of the world and behavior in it. That someone gets a good dollar out of it is no explanation and cannot be any justification of the predictable outcome.
But it's not the content that needs to be regulated. It's doubtful whether any such attempt could be realistic and/or feasible technically. Rather, the companies must be held to their declared purpose and no function of the product can deviate significantly and/or undermine it as long as it remains in the given category. Where "external advertising" is any content presented by or via the product that a user has not explicitly requested, subscribed to or otherwise authorized:
These are the principles of responsible social media technology and industry in this century, and yes, by now there's no avoiding the conclusion they need to be regulated and enforced in any modern democratic society.
The bottom line is, there can be no license to print money by pumping lies through these feeds into the private lives of people. Someone somewhere is responsible.