[@Willy Vereb]
Not rock solid, but hard enough that stuff like avoiding detection while in a spaceship shouldn't be considered as anything but a lost cause.  No FTL exists, but you could if you wanted to beam copies of your mind or an AI at the speed of light between different locations you have the certification for.

I tend to be case-case with tech, as I know people can be rather creative with Sci-fi technology and generally I look at balance more than realism.  So I'm unlikely to allow for instance, Starlifting and kugelblitz black hole generators or Death Stars.