The lawsuit was filed in 2005 when Ms. Zack was at Kohn Swift, and she retained it when she moved to her own firm, her brother said.
Besides the Google case, her brother said, she worked on antitrust, copyrights, and commercial litigation.
Born in Mount Kisco, N.Y., Ms. Zack was the valedictorian at Bordentown Regional High School in 1972 and earned a bachelor's degree cum laude in history at Carleton College in 1976.
She graduated from New York University Law School in 1980, clerked for a federal District Court judge in New York City, and began her career there with the firm of Cleary, Gottlieb, Steen & Hamilton.
A member of the boards and executive committees of Community Legal Services of Philadelphia and Philadelphia VIP, which provides pro bono legal aid, she was a sponsor in Philadelphia Futures' Sponsor a Scholar program.
Besides her brother, she is survived by her husband, Michael Hartung; her mother, Vera; son Benjamin; daughter Claire Hartung; a brother, and a sister.
A life celebration was set from 6 to 9 p.m. Monday, Oct. 15, at Hilltop House, 570 Beaumont Rd., Devon.
Donations may be sent to Doctors Without Borders, 333 Seventh Ave., Second Floor, New York, N.Y. 10001-5004.
Contact Walter F. Naedele at 215-854-5607 or firstname.lastname@example.org.