Mass. Gen. Laws ch. 151A, § 64A

The commissioner shall on or before July first of each year provide to the chairman of the board of assessors in each city and town a list of all employers located in the city and town that qualified for an exemption pursuant to section five I of chapter fifty-nine during the previous year. This list shall be confidential and shall be used only by the assessors or employees designated by the assessors for the purpose of determining eligibility for property tax exemptions pursuant to said section five I of said chapter fifty-nine. Any other use of this list or information contained therein or disclosure of the names of employers on said list to persons other than assessors or designated employees shall be punishable by a fine of one hundred dollars.