Lets face it, we are living in a world full of criminal behavior, much of the activity takes place on the internet. Therefore, we all **should** be concerned with security and making it a priority before you are the victim.
For me security starts with securing my computers, using difficult passwords, and not saving my credit card information on any web site if possible. I've been using the default Mac firewall PF for a long time. However, I have found it difficult to make changes to because you need to use the terminal and you can easily mess up your configuration making it impossible to get onto your WAN or LAN.
I just stumbled onto Murus and it's brother Vallum and suddenly making those necessary changes became simple.. After using Murus for an hour I purchased Murus Pro which comes with Vallum and I will never leave my computer alone without it. With Vallum I no longer needed Little Snitch, which is another great application but it would be redundant running little Snitch along with Vallum. Murus and Vallum work together beautifully because they are develop by the same developers.
****** Need Security? Purchase Murus Pro, it makes configuring your firewall a breeze ******
I am not affiliated with Murus or Vallum developers, just a thrilled user of Murus and Vallum.