Many people ask why you cant secure a High Sec system, for whatever purpose you want to use it for, be that mining, mission running and so on.
The reasons are many:
- You cant shoot everyone due to CONCORD, so NPC alts or other out-of-corp people can easily provide warpins.
- You cannot restrict travel in a system. There are no bubbles in HiSec, so you can't slow people down.
- Hostiles can log out, and log back in to a system easily, appearing in local in a matter of seconds.
- Jumpclones can be used to break any camp, and alts can be used to move ships into the area.
- Anyone with a little experience can run pretty much any HiSec gatecamp in a shuttle or pod, as they can move faster than you can lock them.
In short. You cannot, ever, secure a HiSec system.
LoSec systems can be secured a little, but the lack of bubbles and the existence of gate/station guns, as well as NPC stations with open docking rights, means its still trivial to bypass any security.