I agree with jedisct1 I have and use Little Snitch. It is an important part of my professional toolkit. But I have run into quite a number of non-programmer,

I agree with jedisct1 I have and use Little Snitch. It is an important part of my professional toolkit. But I have run into quite a number of non-programmer, non-sysadmin users who have tried to protect themselves with Little Snitch only to break their computers.