Serious flaws in bluetooth security lead to disclosure of personal data. Bluetooth turns out to have a number of security flaws that allow people within range to access your private data, including calendar events and contacts.
http://news.com.com/2100-1032_3-5153485.html
contains a story about programs that claim to remove spyware, but actually install more spyware on your system.
This article talks about a group that has released a way of hacking a cable modem that allows the hacker to listen to pretty much all of the traffic in the neighborhood.
Techniques like this prove you can never be sure who’s listening to your network traffic. Any sensitive web browsing or email you use should be encrypted, to prevent snooping like this.