While I don't take starcraft2wol's theory seriously, there are a bunch of services that have made phone numbers essentially mandatory. They claim this is to "pr

While I don't take starcraft2wol's theory seriously, there are a bunch of services that have made phone numbers essentially mandatory. They claim this is to "protect your account". You sign up for a Skype account or Twitter account and decline to give your phone number, instead choosing a different form of 2FA? In my experience your account will be blocked for 'suspicious activity' even if you have literally no activity.