WASHINGTON (Reuters) - U.S. Senator Chuck Grassley's Twitter account was hacked on Monday with bogus tweets attacking his stance on Internet anti-piracy legislation, his office said. Grassley, an Iowa Republican and prolific tweeter, had at least eight false tweets posted as he was on a flight heading from Iowa to Washington, spokeswoman Jill Kozeny said. His staff noticed his Twitter account had been broken into a few minutes after the first false tweet was posted and called Twitter to have the password changed, his office said. ...