<A HREF="http://news.zdnet.com/2100-1009_22-5675597.html?tag=zdnn.alert">Computer-security flaws at the U.S. tax-collection agency</A> could expose millions of taxpayers to potential identity theft or illegal police snooping, according to a congressional report released on Monday. The Internal Revenue Service also is unlikely to know if outsiders are browsing through citizens' tax returns, because it doesn't effectively police its computer systems for unauthorized use, the Government Accountability Office found. The report was released three days after the deadline for filing personal income-tax returns, and at a time when concerns about identity theft and computer security are running high.