(Reuters) - Hackers have probed the voting systems of many U.S. states but there is no sign that they have manipulated any voting data, Homeland Security Secretary Jeh Johnson said on Saturday.<div><a href="http://feeds.reuters.com/~ff/reuters/technologyNews?a=q_tSQeRnkNU:uqVDro_Ld-Q:yIl2AUoC8zA"><img src="http://feeds.feedburner.com/~ff/reuters/technologyNews?d=yIl2AUoC8zA" border="0" /></a> <a href="http://feeds.reuters.com/~ff/reuters/technologyNews?a=q_tSQeRnkNU:uqVDro_Ld-Q:V_sGLiPBpWU"><img src="http://feeds.feedburner.com/~ff/reuters/technologyNews?i=q_tSQeRnkNU:uqVDro_Ld-Q:V_sGLiPBpWU" border="0" /></a> <a href="http://feeds.reuters.com/~ff/reuters/technologyNews?a=q_tSQeRnkNU:uqVDro_Ld-Q:-BTjWOF_DHI"><img src="http://feeds.feedburner.com/~ff/reuters/technologyNews?i=q_tSQeRnkNU:uqVDro_Ld-Q:-BTjWOF_DHI" border="0" /></a></div><img src="http://feeds.feedburner.com/~r/reuters/technologyNews/~4/q_tSQeRnkNU" height="1" width="1" alt="" />