Conn. Gen. Stat. § 12-148

(b) Numbers used under subsection (a) of this section may be Social Security numbers established under the Social Security Act, (42 USC 301 et seq.), as amended from time to time. Notwithstanding the provisions of the Freedom of Information Act, as defined in section 1-200 , the tax collector shall withhold from disclosure to any person or state or municipal board, commission, department or agency any Social Security number provided to the tax collector under this subsection or under section 14-163 .

(c) Commencing February 29, 2000, and the last day of February annually thereafter, any person receiving funds from a mortgagor who is an individual with respect to a mortgage on real property situated in Connecticut which funds are to be held in escrow for payment of property taxes shall file an informational return with the Commissioner of Revenue Services showing such mortgagor's name, address, Social Security number and the amount of property taxes paid by such person receiving funds from such mortgagor during the preceding calendar year.