There are gnutella virii, which could be the source of the pr0n spam you mentioned.
(note that the names given by various companies vary)
http://www.europe.f-secure.com/v-descs/gwv.shtml http://www.europe.f-secure.com/v-descs/mandra.shtml http://www3.ca.com/Virus/Virus.asp?ID=9758
Here is <A HREF="http://groups.google.com/groups?q=gnutella+virus+asf&hl=en&lr=lang_en&selm= xE%25Y6.7479%24Cc3.1241047%40news2-win.server.ntlworld.com&rnum=3">some info on averting the virus in .asf files</A>.
Whether it's a virus or the limewire server you mentioned, there's a lot of it about. There is one particular form that I get constantly (mandragore - see links above) in my search results - it answers queries with search results which match exactly the text you searched for. Several copies are returned, with different extensions and appropriate file sizes for the various extensions.
This is bad if you searched for "Metallica - And Justice For All.mp3" because you won't be able to tell which are genuine results in some cases. But it is good if you are smart and search for "mp3 justice metallica all", since the file will clearly be not what you are looking for but a virus.
Of course it is really a problem if you have automated search + download, and not done any sanity check on the search results using a technique like that above. I don't know if current auto-download clients support this type of check, but it would be useful.
Well spotted though on the limewire server. This could also be easily coopted to do the job. I've wondered for some time whether people have their own customised clients which server this way, but no that limewire has provided it, it's a moot point.
It would be desireable if the articles served from a server such as this were marked clearly, something like 'Dynamic content: rest of the filename.ext'.
Also desireable that the server should have a unique ID, not just the same ID as limewire (I don't know if it has or not).
Nos