Social Networking and Web Security

Working on a professional networking website Skillda, I was always confronted with a question from my friends about a missing feature. In Skillda there is no option to import contacts from any of other networking sites or email account.

Almost all of us are familiar with the large number of automated invitations from the networking sites these days. Some of them even send mail repeatedly till you join the network. For doing this, these sites ask you to enter your username and password of a different website or email, then crawl through the website and get the contacts. This is exactly what concerns me. I just cannot believe how someone would entrust a third person with the username and password of their email account giving access to important documents like bank statements and other personal stuff. And that too just in exchange of the ease of importing your friends or contacts to a social networking site!!

I am wondering if the concept of web security has gone skewed over the years or is it that social networking boom is making people blind?