Pinstagram is a wonderful site and I use it all the time to view my wife's Instagram photos! But are you guys worried at all that the name infringes on Instagr

Pinstagram is a wonderful site and I use it all the time to view my wife's Instagram photos! But are you guys worried at all that the name infringes on Instagram's trademark? It's one thing to rebrand a website, but it's a lot harder to rebrand an iOS app. Or maybe you guys are already talking to Instagram and/or Facebook about joining their team, and they're ok with you using the TM in the meantime?