Forum OpenACS Q&A: Security issues with user submitted pages

Hi.

I have to publish pages created by users (they're supposed to be
kind of articles). The process consists of copying the files in a
directory under www.mysite/users/one_user to newly created directory
under www.mysite/.

What are the security issues i have to look at? The few ideas i had
where: copy only html, txt, gif, jpeg, pdf and some other type files,
in the htmls strip all the javascript and java, and not much more.

Thanks in advance,

Jorge