I know how to do it in perl but would like to know how to do it in XOOPS modules such as section and news. This is what i want to do:

Add a short copyright sentence to the end of earch paragraph. The text will be the same color of the page, so it won't interfere with viewing. But when you cut and paste the article, it shows and it's annoying to the people who don't respect your copyright.

i know they can remove them. But it makes it a little bit difficult for the "pirates".

Your help will be appreciated.

I really don't believe it's worth the hassle, but since you want help and not my opinion, here's my 2c

1st: Smarty allows you to filter/change/add stuff to your output easily (check my OldTimes theme, it removes img tags), is easier to understand than plain PHP and can be hacked in themes and/or templates
2nd: you don't want to hardcode background colors or to add the copyright text to your actual data in DB (you'd be the most annoyed by that )

So I'd go for a theme based solution (because themes can deal with BG colors), but you might need to add "clues" to templates...

Do you have a test server ready?