Dear Instawallet,
Yesterday I discovered a security flaw with your site, I spent nearly 6 hours working with David Francois Chief Technology Officer at Paymium
The security flaw impacted roughly 3000 people that use Instawallet and indirectly Paymimum, Paytunia, Instawire, and Bitcoin Central as all of these companies are yours.
After 6 hours of work, I can finally confirm that the security flaw is fixed. The security flaw was serious in my opinion, As all the URLs of roughly 3000 people were publicly listed.
http://www.adaptiveglass.com/?p=656