On the Map - A Guilt Trip, Data Collection Exercise or New Idea?

Fundraising Technology & NFP 24/7: The NSPCC is using Google Maps to create an online supporters map. You are encouraged to pin yourself on the map using your postcode. Once you have signed up NSPCC then try and get you to donate, volunteer, fundraise or campaign by telling you how many other people in your area have pledged to do the same.

Nice idea and nicely executed, but I am concerned that this is just another data collecting exercise by the charity, and another opportunity to use guilt to make visitors take action.