This cannot be explained in great detail
From China Digital Space
这事儿不能说太细 (zhè shì bù néng shuō de tài xì): This cannot be explained in great detail
On January 12, 2009 CCTV ran an investigative piece on the collection of tolls in Shanghai and Tianjin at a time when such tolls were to have been abolished. When asked how much debt for road construction was repaid each year, Liu Bo (who bears the grandiose title of “Tianjin City Civil Affairs Department Public Road Management Bureau Toll Rate Office Deputy Director”) replied, “This cannot be explained in great detail.”
Netizens who perhaps were annoyed by vague government statements and a lack of transparency latched onto the phrase which was dubbed the first “viral internet phrase” of 2009. People use the phrase in internet posts to mock vague government statements or as a sort of inside joke without political overtones.