Get and Set clipboard with JavaScript

I have seen a few threads explaining that Flash can be used to set the clipboard data in Mozilla and Internet Explorer, it's easy, etc.

For example Greasemonkey\JavaScript Copy to Clipboard button

However, I would like to read the clipboard and remove certain ite开发者_运维问答ms before setting it. Is there any way to do this?

So.. Is it possible then to detect whether copying and pasting is occuring? Then redirect them to another URL?

Reading the clipboard is a pretty big security issue. Even if you can do it, it's not considered a friendly tactic, and I would advise against it, especially if you plan on changing it.