You can’t realistically stop people copying text, if you don’t want it copied, either make your content private(so only registered members can see it), or don’t put it on the web.
There’s ways with javascript to at least stop ‘select all’ i believe so I’m sure there must be some type of script to do that part.
Realistically speaking, i do not personally think it’s a website’s place to tell the browser what functions it can and cannot perform. Secondly, technically speaking, whenever someone views your site, they are actually downloading the content of that given page in order to view it, so they’ll already actually have a copy before any right-clicking or selection is performed on the page.
If you’re still certain you want such a script, this would be a good place to start in finding one.
http://www.google.co.uk/search?q=javascript+disable+select+all
If you need help implementing the script, i’d suggest a read of the following page.
http://codex.wordpress.org/Using_Javascript
NOTE: There’s some useful links at the bottom of the codex page(linked above).
Thanks, I just figured if these plugins could stop copy , including key controls then it should be the same for select all.