The reception to Mixel has been fantastic, but there have been some complaints about the fact that the app requires a Facebook account in order to be used. There is a good reason for that: Facebook lets us build the Mixel experience around real names, which is powerful for many reasons but most important to us in that it helps protect against the abuse of your personal photos. Lascaux CEO and co-founder Khoi Vinh has posted an explanation of this reasoning here if you’re interested.