whose numbers are those are they stolen?
No they are not stolen.
Text message confirmations? What's that? You mean like when you sign up to a website and you they need your number? 0.01 seems pretty expensive for that to be honest.
Yes, usually for signing up for websites but it doesn't matter for me what you use them for.
Only requirement is they doesn't cost anything to me (if they aren't free they will be automatically blocked)