FWIW free-speech absolutist America already has this kind of law on the books. It's called DMCA 512; it only requires the allegation of a copyright infringement in order to trigger the same kind of censorship[0] as NetzDG appears to do.
If you have been unfairly targeted, you can counter-notify, but that requires doxing yourself. There's also a subpoena process to explicitly request the unmasking of anonymous users[1]. YouTube is chock full of DMCA extortion scams that specifically target smaller channels and demand payment to avoid getting one's channel deleted. Those scams work precisely because Google has an active and ongoing[2] policy of summarily executing rule breakers without explanation or recourse.
Laws like DMCA 512 and NetzDG only have these kinds of censorious effects[3] specifically because social media is itself a kind of scam. Regular publishers actually spend money to fund the creation of creative works that they expect to make a profit off of; platforms create a container and incentives for other people to fill it with amorphous "content". Publishers take on the risk of publication, including defamation and copyright liability; while platforms are set up specifically to shift that liability onto people who cannot bear that burden. The end result is that most people on social media choose to self-censor; even if they have no intention to defame, misinform, hate upon someone, or infringe a copyright.
[0] We are assuming for the sake of example that the targeted content is novel speech and not infringing. America does not consider copyright infringement to be speech.
[1] The Darkspilver / Jehovah's Witness case is a prime example of how to abuse a DMCA 512 subpoena request; we're lucky the courts came to their senses and decided not to unmask them.
[2] As far as I can tell, since the company's founding
[3] For the purpose of discussion I'm not going to argue whether or not hate speech or misinformation should be censored, we're just going to assume that it should.