That's interesting. I checked and it is happening to just this one user and has affected their posts in at least 5 different threads.
I think they have a virus on their computer, that is causing their browser to add malicious code to the things they post on the web.
It is not their fault, but that's probably what is happening here.
We never noticed it before because I have always quietly removed HTML tags from all posts. Recently I made a change to allow HTML tags to stay but render as text rather than render as HTML.
Anyway I'll edit and fix the images she posted.
