I like to have a wide social network but I often organise mycontacts according to people that I share my core interests with. This helps me keep in touch with their projects and exchange information regularly. I neverthless like having a wide and diverse social network as I have often had unexpected yet insightful exchanges with someone from outside my core network group.
I am more of a focussed online networker. Some people want to share everything with everyone. I often only post online about things that I feel are pertinent. I guess resilient networks rely on matching people with similar interests while also providing the scope for sharing your thoughts with a wider audience to allow you to expand that network of core interest groups.
There are often dangers involved with any online entreprise. I mainly try and deal with it by being careful about the kinds of applications and services I sign up for and the level of personal information I disclose about myself on social networking sites.