I'm a reasonably well educated human living on Earth. What's to stop me from replicating starship parts until I can make my own Starfleet?
Let's say I decide I've had enough with this whole Federation business and that humanity would be better represented by a Starfleet that follows my particular ideology. Assuming I could get enough people for crew and support, why can't I start my own Starfleet?
I could replicate ship parts until I have a couple vessels. Go to new worlds and present myself as the official first contact of humanity. I could fly to Vulcan or Bajor and tell them no actually my organization represents humanity.
Raw material, I would imagine. I don't remember exactly how replicators work in the Star Trek universe, but they either rely on energy, a raw base material, or both. You can't create something out of nothing so you would need a significant supply chain to produce your fleet.
If it were that easy, every rogue organization in the galaxy would have already done it before you.
The Laws of Thermodynamics say you will always lose some energy to heat when energy is used to affect a change. I have to imagine this would be particularly so when energy is converted to matter since that's very involved, but I'm not a physicist so I can't confirm that.
Come to think of it, this means that industrial replication plants and shipyards would likely be incredibly hot places, due to the inevitable loss to heat in replicating massive components.
My understanding is that replicators restructure atoms. In which case an asteroid would be plenty of material for a ship, even if some of it is lost in the process.
Could I replicate charged batteries, then plug them in? Or would it take more energy to make the battery than you could get out of it? After all a battery is just a chemical reaction.