The computer-animated “Dancing Baby” may have been a hit on the Internet and on “Ally McBeal,” but he caused havoc Friday morning in Tokyo when the character showed up on the Japanese government’s Trade Ministry’s homepage. Hackers are being blamed. “It’s so embarrassing,” Trade Minister Takashi Fukaya told a news conference. All this week, Japan has been suffering from raids on official government Internet sites. Some hackers left messages attacking the government, others inserted links to porno sites. As for the baby doing the cha-cha, a trade official said he was quickly removed.