davemark, 
Back in the day, phone numbers used to belong to carriers. So if you switched carriers, you changed phone numbers.
Feels like the same situation with social networks.
If I move to a new social network, all my followers have my "old number".
Imagine if there was a level of indirection (like an Apple ID or an email) that always led to my current social network.
Impossible? Dumb idea? 🤔
#Socialmedia #Social