There are as one another factor that could keep these girls safe that is the existence of twelve poeple that came with them.
Lihn, Tom and others were much more valuable so much so that Samuel went out of his to hire them with undisclosed amount of money.
These people barely came out of the second mansion where their base was situated. Maids and butler who took care of them only needed to provide food and clothing, they would take care of their basic necessities after which Linh and others would practically spend their time in front of the screen.
The facilities were upgraded to the highest level possible. Samuel was even willing to buy a supercomputer for them to research but he knew his movements would be discovered making other people alarmed about what he was going to do with it.
