Liu exposed Bloomberg's corrupt pet project City-Time. CityTime was intended to prevent employees from stealing City Time (i.e., taking long lunch breaks, etc) by having city employees punch in, either digitally on their computer work stations or through hand scanners.
Ironically enough, it was the company that installed the hardware that ended up stealing "City-Time", and a project that was suppose to cost the city 30 million dollars and prevent the working class from coasting, ended up costing a billion.
Liu exposed the fraud and has received NO LOVE by any of the daily rags, since. It's my guess that Bloomberg has the newspapers in his back pocket, especially when you consider the fact that the newspapers have been in the red for some time now and Bloomberg has never had any quarrels with "purchasing" his objectives.
What's funny is that every year during the holidays Bloomberg sends out letters to every city agency, warning them that it is illegal to accept any gifts over 20 dollars - which would constitute a conflict of interest. But the fact that he literally owns a huge media conglomerate while Mayor of NYC is no conflict. Maybe he was busy running he private businesses while City-Time was getting cleaned out dry?