What are they thinking?

There's a new social networking site that just made me think, "What are they thinking?!" This is Blippy, which apparently lets you broadcast to the entire world what you're buying. What worries me about this is the fact that the payments information that this service needs to use is fairly sensitive. How are they getting this? Is the process secure?

Here's what the Blippy web site says:

Blippy is a fun and easy way to see and discuss the things people are buying.

Automatically share your favorite purchases from iTunes, Amazon, Zappos, Visa, MasterCard, and more.

Yikes! Are they actually getting data about purchases from Visa and MasterCard? This is one (of many) social networking site that I definitely won't be signing up for.