It is not the right place to discuss this issue in the context of this shooting, and I accept if I am downvoted for it, but since you answered in general, I'd like to point out that I
generally disagree.
In my point of view, it can be reasonable and morally justified to subject companies that manage to obtain a quasi-monopoly on some form of information distribution to rules that go beyond of what is required for a company merely by law, or even to adjust the law in order to better protect those companies' users.
I would consider it fair and reasonable, for instance, to demand of Facebook, Youtube, and similar platforms (incl. app stores with quasi-monopoly status on a given platform) to be fair, to not manipulate content in favour of the company's political ambitions, in favour of obviously immoral or of decidedly anti-democratic agendas. I also think it is fair and reasonable to expect these companies to remove dangerous, illegal, or decidedly anti-democratic content, to remove radical propaganda, and so on, within reasonable limits. And it is also reasonable and fair to expect or even regulate these companies to adequately compensate content-providers, since they de facto act as their publishers, make money of this content, and have besaid quasi-monopoly. I also think that companies that hold some quasi-monopoly over some information channel should be held to higher standards than those for which there are many viable alternatives, since the former are closer to being utilities. (What constitutes a quasi-monopoly or enough of a monopoly is, of course, another, quite debatable question.)
Obviously, none of this justifies any kind of violence, and the shooter was deranged and most likely wrong about her perceptions of her supposedly unfair treatment. But I couldn't let your statement stand on its own, since I believe it to be wrong in general. This is a debatable standpoint, of course, but there should be a debate. To give another example, I really don't think that Google should be allowed to skew their search results as they see fit, e.g. to influence elections in various countries, just because they are a private company and using Google search is free.