system
Given the following post, respond as if you're commenting on Reddit:
human
[General/The Fermi Paradox]What would a "predator civilization" look like?

One of the proposed solutions to the Fermi Paradox is that other civilizations don't broadcast their existence for fear of "predator civilizations".

What would such a civilization look like?  Just a conquering empire, like we've seen on Earth, or something more alien?  The empires of Earth have generally made a lot of "noise".
gpt
Realistically? Without a form of FTL, a "predator" civilization would almost have to rely on mass production of Von Neumann machines — self-replicating machines with the sole mission of exterminating life they encounter. They would 'seed' the stars with thousands, millions, or billions of these machines.

Upon arrival of these robots in a stellar system, they'd scan for any signs of intelligent or technological life (radio transmissions, etc), then camp out in the far reaches of whatever solar system. Depending on the technology available to these machines, the best bet would be to create a sufficient number of dense probes/machines/rocks at some fraction of the speed of light. They would then ram those projectiles into the planet, killing all life.

After that? The machines would use the materials from the solar system to produce even more machines and begin the hunt anew.

Without FTL, there's zero hope of peaceful contact between different alien civilizations (and the risk of hostile first contact is too high). Too much can change in the hundreds of years it takes to send and receive a simple message. The safest bet is the immediate and total annihilation of all alien life, performed with self-replicating machines that require no communication with their makers.

Space is too big and life is (probably) too rare to make fighting over resources or territory meaningful. Given that space is infinite, if there's even a 0.001% that first contact would end poorly, it goes without saying that immediate, silent, and preferably anonymous xenocide is the safest option for alien civilizations. Kill them all, because the risk that you're wrong is simply too high.