[jburgess777]

A long time ago, a bug in Firefox let a screenshot be taken of data outside the browser window:

"This issue allows attackers to capture screen shots of private or confidential information"

https://blog.mozilla.org/security/2011/06/16/webgl-graphics-...

[FraKtus]

I suppose this is more about reading another texture than the one you are supposed to use. GPU memory is flat, and there is no concept of process memory up there.