Legally, the broadband contract holder is liable for the content accessed over their connection. Handing out the WiFi code gives no way of knowing who has accessed what.
Our service blocks adult content, and has a host of settings to block other types of content if you want.
The guest network is also completely firewalled from the rest of your connection, so your own wired computers, tills etc are safe and secure.
Seperate policies can be setup for staff Wi-Fi so you can control content access seperately if you wish.