I just want to know how those people behind bitcoin secure the money they will invest because as far as I know there are lots of hackers all over the world.
Indeed there are a lot of hackers and eve intelligent hackers in the world but you can secure your bitcoin account by choosing a unique username and password. There are a lot of things to be different and unique so that hackers will not have an access in your account. However, botcoin has a very complicated system which prevents hackers from invading. I believe it is difficult to hack so have faith and just do not worry.