有多少人喜欢于朦胧
[yŏu duō shăo rén xĭ huān yú méng lóng]
Translated as 'How many people like Yu Mengmeng?' It indicates that this username references admiration for Yu Mengmeng (a real or fictional character). Often such usernames are used by fans to display their loyalty or affection for a particular artist or actor.