Is it time to get a firewall for your home or home-office?
Ask yourself, what would you do if someone took over all of the computers/devices connected to the internet in your home or home office.
Whatever your answer might be, it will almost certainly end with you engaging in a very costly process of decontaminating and recovering data from your devices. Avoiding this kind of unforeseen cost and inconvenience, not to mention the threat to your personal information, can be made more likely by employing a firewall.
The US Computer Emergency Readiness Team (US-CERT) issued a fantastic article that helps to explain what firewalls do, the types that are available, and how to choose the right one for your situation. I highly recommend reading it.