password theft

As I am reading news these days, I hear people stealing the passwords. Many of the officials have lost their password in United States. Many accuse China for the password stealing. But no clue whatsoever that, who is doing this malice work. Last two weeks three or four times I have changed my password. But still I am not satisfied. I try to change it again and again. One password was there for years, but I had not changed it. But now, the new phenomenon makes me to change the password on every alternative day.