2. Whether to detain depends on whether it constitutes a crime. Refusing to return the mobile phone is illegal, but it does not necessarily constitute a crime.
Whoever illegally takes forgetting things and buried objects of others for himself and refuses to hand them over in a large amount shall be punished in accordance with the provisions of the preceding paragraph.
3. Picking up a mobile phone constitutes a crime, and the following conditions need to be met:
(1) reached the standard of large sum;
(2) Intention of illegal possession;
(3) The victim files a criminal private prosecution.
Legal basis: Civil Code of People's Republic of China (PRC).
Article 314 Lost Property Found shall be returned to the creditor. The finder shall promptly notify the obligee to collect or deliver it to the public security and other relevant departments.
Article 315 If the relevant department receives the lost property and knows its owner, it shall promptly notify it to collect it; If you don't know, you should publish a recruitment announcement in time.
Article 316 Before the finder delivers the lost property to the relevant department, the relevant department shall take good care of it before finding it. If the lost property is damaged or lost due to intentional or gross negligence, it shall bear civil liability.