When copying some content on a web page, it can happen that the clipboard contains more than what is visibly selected.
This is done for
- promotional reasons (e.g., an attribution line with link, appended, prepended or even injected somewhere inbetween),
- malicious reasons (see for example the proof of concept that you should never copy-paste from website to terminal),
- spam prevention reasons (e.g., for protecting an email address),
I’m looking for a Firefox solution (preferably an add-on), which must be FLOSS, that can notify/warn me somehow as soon as I have copied something invisible.
(Some time ago, I suggested to include this in NoScript, but it’s probably not going to happen.)