[m-s-y]

FWIW, what you’re seeing is likely just the cached thumbnail that iOS creates for the app-switcher UI, not an interactive web session.

[pornel]

Yes, but still if you have somebody looking over your shoulder, it can leak whatever you've been looking at.

There's a way to block that entirely for "secure' apps, but iOS could be smarter about this, and cache some stripped down view or expire that cache quicker.

[DavideNL]

This is also the case for FaceTime; The last image the camera captured will stay visible in the app switcher like forever... so other people who use your iPad / iPhone can see it.

[f1shy]

Yes. Something like that, but can reveal a lot of the site you were in.