Visitors come to your website - but how are they connected to the Internet when they come? That is the key.
If the connection is public - it is unprotected and can be easily hi-jacked by a "Wi-fi Attacker". Here are just some of the unwanted results that might occur:
WHAT IS THE SOLUTION?
The answer is to use TLS/SSL for all websites, including the home page. Why? HTTP is the main way we commonly connect to most websites as we surf the Internet. But HTTP is unencrypted. That means it is not secure, it is not hidden or coded, and is open for all to see. Anyone who is on the same network connection can read it. When you implement TLS/SSL, you truly lock out spies and can surf in privacy.
What is TLS/SSL?
DISPELLING MYTHS
Previously, it was thought that certain methods protected us from the problem. For example:
How to Secure Your Wireless Home Network: 8 Steps (with Pictures)
How to Stay Safe on Public Wi-Fi Networks - Lifehacker
5 Ways to Secure Wi-Fi Networks | Network World