The activities of the Union Bank of Switzerland during World War II were not publicly known until decades after the war, when it was demonstrated that UBS likely took active roles in trading stolen gold, securities, and other assets during World War II.[87][88] The issue of "unclaimed property" of Holocaust victims became a major issue for UBS in the mid-1990s, and a series of revelations in 1997 brought the issue to the forefront of national attention in 1996 and 1997.[89] UBS confirmed that a large number of accounts had gone unclaimed as a result of the bank's policy of requiring death certificates from family members to claim the contents of the account.[90][91] UBS's handling of these revelations were largely criticized and the bank received significant negative attention in the U.S.[92][93] UBS came under significant pressure, particularly from American politicians, to compensate Holocaust survivors who were making claims against the bank.[94]