Which of the following acts of using the works of others is most likely to infringe on the privacy of others? (1)To study the types of commodities recently purchased by office workers, Chia-chia clearly informed them of the research purpose when distributing the questionnaire and promised that personal data would be treated anonymously. (2)To distribute a questionnaire to university lecturers, Ta-tung collected lecturers' emails that are publicly released on the Internet. (3)To study mobile phone use and addiction among female college students, Hua-hua secretly filmed the daily routines of roommates in her dormitory, but she promised herself that the video would not leak out. (4)To study the online behavior of netizens on Internet idol fan pages, Hsiao-wei collected and classified screenshots of netizen likes and comments