Yesterday, Google launched a Play Music plan that lets up to six family members listen to music for $15 a month. But it also quietly unveiled another interesting feature: Family groups and payments. You first set up a family group by inviting your kin or friends, then add a family payment method that's separate from your personal payments. From there, any member of the group can buy content without your say-so, though you will get an email confirmation for each purchase.You have to be 18 to sign up, and purchases are limited to apps, books, movies, games, TV shows and magazines. Family members can't buy devices from the Google Store or use it with Android Pay. In-app purchases are also disabled by default, so your idiot nephew can't make you the not-so-proud owner of a lollipop hammer. You have to go through the Play Music signup process to enroll in family payments, but since they also work for apps and other items, that might change. Signup instructions are here, but for now, the feature is only available in the US, UK, Canada, France, Germany and Australia.