Yeah, when these Java consultants did that in a search they built for the company I work for, I was amazed. I called them on their mistake and they first claimed it wasn't a problem and then claimed that it was our fault for not specifying in the contract that they had to support multiple browser windows! (The old "spec was bad" defense.)
in reply to Re: Store results by search term, not session ID
in thread Database searches with persistent results via CGI
I think the problem in their case came from how much the Java servlet session interface looks like a cache. It's very tempting to just cache things in it rather than build your own proper cache. This is something to be wary of with Apache::Session too.
(Incidentally, some of the other posters did mention the idea of using the search terms instead of the session. They just weren't as clear about why.)