I've read many thread the last few daze about ppl being scanned. Here is a very interesting article about hacking activity over the net thanx to the 4 years honeynet project experience.
http://www.webtalkguys.com/article-honeynet.shtml

Thats one of the amazing things. If you put the computer out there with no perceived value, it will probably get scanned 10 20 times a day. This is any system. Im not talking about corporations. Even a home system on cable, DSL or ISDN a dedicated connection they are also getting scanned 10 20 times a day . The hackers are getting very active because its very simple to hack. You just download the tool and run the tool.
Thats one of the interesting things weve learned. Because of these honeynets, we see what these guys do afterwards so we can monitor their motives. There is a misconception that people think these attackers are misguided youths exploring the Internet. The reality is that the vast majority of these individuals have criminal intent. They are out to make money.
[...]
People scour the Internet for e-mail addresses to build databases of stolen e-mail to sell to spammers. Stolen PayPal accounts or stolen eBay accounts there is a tremendous amount of criminal activity going on. Its extremely hostile.
brrr....