BT Wifi hotspots intercept and redirect google SSL searches

I wouldn’t have noticed them doing this except google told me. That does beg the question, if I was buying something on a website and didn’t notice the redirect from HTTPS to HTTP, could other people on the hot spot be snooping my transactions?

I guess BT have a good reason for doing it but this reminds me I must always connect to the internet via a VPN when on a public hotspot.