Dear-
Attached is the photo asking iphone/Android for IB login.
1) Probably customer should leave IB, in case he does NOT use cell. Is it true?
2) Possibly he does not want to release phone number for his phone, even if he uses phone.
3) If other brokers in US asks phone number together, he should leave US stock market? Possibly forever?
Appreciated if anyone shows me relevant explaining link or shows me any law/code/… .
PS) I understand that we should give SSN for opening a new…