Feeding specific binary data to a UTF8 PrintWriter causes it to go haywire and write out a steady stream of nonsense (0, I think). The was tracked down in Azureus by Jon Burgess. He created a simple test case to reproduce the problem. The test case is attached to this Fedora bug...
https://bugzilla.redhat.com/bugzilla/show_bug.cgi?id=187698 -- Summary: UTF8 PrintWriter goes haywire Product: gcc Version: 4.1.0 Status: UNCONFIRMED Severity: normal Priority: P3 Component: libgcj AssignedTo: unassigned at gcc dot gnu dot org ReportedBy: green at redhat dot com http://gcc.gnu.org/bugzilla/show_bug.cgi?id=27171