Sometimes, you may need to block someone on Hangouts. It is an easy and quick process: Open the Hangouts application on your Android device and a Hangout conversation. Tap the 'More' button and then the 'People' option. Choose the user you wish to block and tap the 'Block' button. That's it. To unblock him/her, open the Hangout application> tap the 'Menu' button> tap the 'Settings' option> choose your accounts> tap Blocked contacts> tap the 'Unblock' button next to the person you want to unblock.