Such complement cannot really exist. If it will exist and actually be effective, the technology as a whole would be pointless. An analogy can be made to WhatsA

Such complement cannot really exist. If it will exist and actually be effective, the technology as a whole would be pointless. An analogy can be made to WhatsApp. It's known to be used to coordinate terrorist attacks in Europe yet not a single government intelligence agency has managed to legislate Facebook into opening a back door. Because a backdoor makes encryption quite pointless. Similarly, the case with Apple. Whom categorically refuses an unlock ability to authorities, and so far has won. There's no public outrage. The public seem happy to be protected from the prying eyes of their governments. And I guess the public implicitly accepts that as part of this protection, some very nasty stuff goes around these same platforms. That's why I believe we should separate content extermination (which is fully impossible) from hiding said content from view. The latter is doable and common. For example, terrorist videos are almost immediately removed from social media platforms upon detection. This stops it from spreading and its damage and shock effect is contained. However, should you specifically seek out such videos, they can still be found in several places, and you don't even need to go to the darkweb. Censorship, in the practical sense, should be seen as hiding from view. Not deletion.