Comment by dotancohen

  > old telephone lines did not disclose info about me with merely my phone number.

Old telephone lines most certainly disclosed additional information about you. Who you contacted, when, how often.

Did you call that drug dealer every Tuesday evening? Looks suspicious. Did that criminal call you the day before he robbed a store not far from your home? Looks suspicious. Do you call Pakistan twice a week? Looks suspicious. Have you ever called a suicide prevention hotline? A bank other than your own? A mosque? An independent political party?

Your POTS phone was always revealing information.