wifi没密码才是中国好
[wifi méi mì mă cái shì zhōng guó hăo]
Loosely translates to 'WiFi with no password is what makes China great'. This is somewhat sarcastic about open-access public WiFi which was a trend during a certain era in urban regions in China and implies ease or quality of life, but it's also an idiom implying how good or convenient things are when they're freely accessible without restrictions, like the dream of an open society without limitations.