Safari sidebar silently loads all your bookmarks

Safari was inactive, in the background, with no windows open, when out of the blue I got a Little Snitch alert: Safari wanted to connect to the URL http://192.168.0.1/favicon.ico for some reason. The IP address 192.168.0.1 is private. I quickly realized that http://192.168.0.1/ was one of my bookmarks, for the web interface of my router. I had recently been looking at my bookmarks in order to answer someone’s question on Reddit about Safari bookmarks, though I hadn’t looked specifically at that particular bookmark or its containing folder. My rules in Little Snitch mostly allow Safari to connect to the web, because of course Safari is a web browser. However, I do have a rule to ask about outgoing connections to the local network, triggering the alert above. Sometimes malicious websites attempt to probe your local network, so I want to be alerted if that happens. When I checked Little Snitch Network Monitor, I discovered that Safari apparently connected to all of my bookmarks within…