According to a report published in the "Network World", the biggest vectors for web hacking in 2009 were social networks, SQL injection, cross-site-scripting, authentication abuse, and cross-domain-request-forgery.

The concern about social networks is something I've written about before. I use twitter to announce my money making projects, linked-in to outline my professional achievements, and face-book to socialize with others. However; I do not tweet my intimate thoughts, put a detailed resume on linked-in, or reveal anything too personal on my FB wall.