This justlinux article discusses the security (or lack thereof) of a home DSL connection, and how the author went about detecting the intruder. "What I found in /dev/.oz was a real shocker. There were several binaries with names like, scan, sniff, fix and several others. I opened install. ... The hacker changed the index page for one website, so I take it down and call the user to tell him re-publish his site. The other three sites were OK -- all three were PHP sites using pattern files stored in unusal directories."