Firewalls are another aspect of security worth considering. If your computer is connected to a router with a built-in firewall (most routers contain firewalls by default), then you are already reasonably protected from the outside world. However, a firewall in your router doesn't protect you from hacking attempts from inside your local network.
Note
Although activating a firewall helps on a portable device used on public networks, it's still not a substitute for using a VPN service to pass your Internet traffic through an encrypted tunnel. If you use a laptop in a public place such as a Net Cafe, consider using a VPN service to protect your machine from packet sniffing tools used by someone around you. Sometimes, the biggest hacking threat may even be in the same room as you, without you knowing it.
Linux Mint comes with a preinstalled firewall known as iptables. The iptables firewall is very common in the Linux world and is installed by default...