Only if you have their username and password.
Nothing… If you found this utility helpful, we're open to donations though!
It varies. There are several factors including how many tracks/playlists you have and how busy the network is. Due to limitation from the various services we can only process so many transactions at a time.
We only store what's necessary to complete a migration. If you provide us your email or phone number so you can be notified when a transaction is completed we promise not to share it.