It may be useful for future reference to post some advice on using other people's written work ... with no criticism implied of RP, who I'm sure was doing his best at the time. It's brought wider issues into focus.
For general background on what is plagiarism, see a handout on plagiarism by a university teacher at http://science.widener.edu/svb/essay/plagiar.html
. Note particularly the advice under â€˜What to doâ€™. This is really helpful for those of us who prepare material for publication to parents, prospective students, etc, and online websites too.
for a useful article which additionally addresses the issue of web plagiarism (also known as â€˜online plagiarismâ€™).
Note the section on online plagiarism from that article, and actions that can be taken:
Since it is very easy to steal content from the web by simply copying and pasting, the problem of online plagiarism is growing. This phenomenon, also known as content scraping, is affecting both established sites  and blogs ... .
Free online tools are becoming available to detect and prevent plagiarism , and there are a range of approaches that attempt to limit online copying, such as disabling right clicking and placing warning banners against plagiarism on web pages. Once identified, instances of plagiarism are commonly addressed by the rightful content owners sending a DMCA removal notice to the offending site-owner, or to the ISP that is hosting the offending site.
[http://en.wikipedia.org/wiki/Plagiarism, 9 October 2007]
(DMCA refers to the US btw). In the EU the equivalent law is the EU Copyright Directive.
I hope this is useful.