Ebola is a nasty disease to get. It's scary. But as a weapon, it is probably not likely. Ebola is a difficult malady to weaponize and deliver efficiently.
I think about the characters I've created and then I sit down and start typing and see what they will do. There's a lot of subconscious thought that goes on. It amazes me to find out, a few chapters later, why I put someone in a certain place when I did. It's spooky.
There was a time when nails were high-tech. There was a time when people had to be told how to use a telephone. Technology is just a tool. People use tools to improve their lives.