>>/39655/
When a website loads scripts can be executed automatically. Or when clicking reply, I think they need to reply and not just browse.
Basically, when the user clicks reply, the click on that button initiates an upload of the contents of the form, the text, the image, etc, but other actions can be tied to the use of the button, it could tell the browser to change background color for example, or close the page. By that effort hypothetically they could run a script that do whatever to mine cryptocurrency.