Here Anbox install problem @karel said:
WhatsApp also asks if you want to give the app permission to access the files on your device which is another security risk in my opinion. I think it's OK to give WhatsApp permission to access the files on my phone, but I don't want to give the app permission to access the files on my computer. Permissions are a matter of fundamental importance in Linux. You should be very careful about giving permissions to an application that it doesn't already have by default, and the telegram-latest snap package in Ubuntu 16.04 has better support than WhatsApp including Telegram Calls voice calls which are currently available to users around the world.
I'm wondering, is there a way to make absolute sure that apps installed in Anbox cannot gain access to files on the computer? Maybe running Anbox in Firejail can prevent this?