Bill Cooper talked about monolith symbolism. He did an in depth analysis of the movie 2001: A Space Odyssey.

In the movie, all movie all the primates are equal. One group of the primates then touches the monolith. They gained special knowledge and became superior to the others. They then beat and killed a non-monolith monkeys with a tool to demonstrate their superiority.

These monoliths that are appearing are likely black hat comms. They're stating that they're in possession of special knowledge and are therefore superior. Moves and countermoves.