Q: I found an item in public square or street. May I keep it?
A: If most of the people who assemble there or pass by are Jewish, we do not presume that the owner has yei’ush, so that hashavas aveidah applies (C.M. 259:3).
However, if most of the people who assemble there or pass by are gentile, we presume that the owner had yei’ush once he became aware of the loss, so that you can keep the item, even if it has identifying features (ibid.).
If the owner made efforts to search for the item, some maintain that we cannot presume yei’ush, since he demonstrated otherwise. Others maintain that even if the owner began searching, it is like he is making a futile attempt to restore lost property. Yet others distinguish between when he began searching immediately, in which case we cannot presume yei’ush, and when he began searching only later, in which case we presume that he already had yei’ush (Pilpula Charifta B.M. 2:6 [1]; Tzemach Tzedek #89; Drishah 259:3).
