There are two different things: one is modifying the clipboard from JavaScript. IE used to be able to do that, I don't know if it's still the case. I'd be very

There are two different things: one is modifying the clipboard from JavaScript. IE used to be able to do that, I don't know if it's still the case. I'd be very surprised if Chrome allowed that… The second thing is modifying the selection through JavaScript which is indeed possible. However, removing that ability doesn't really solve your problem because you could imagine having white small text embedded wherever you select which would end up in your clipboard without your knowledge.