. . . right to privacy

. . . confiscation done by a private individual as far as i read is valid and is not covered by our laws on illegal seizure, question is
1. can this be used as evidence in court?
2. if the confiscated object is a cellphone, may the private individual who confiscated the same look into the contents of the phone, without the prior consent of the owner and without violating the constitutional right to privacy
3. what if the phone was used in violation of RA 9995 or the anti-voyeurism law, and the accused was caught in flagrante delicto, may the private offended party on his own open the files of the phone and are these data admissible as evidence?

1) yes it can be used as evidence
2) there will be a violation to privacy, and you can be civilly or criminally liable for taking the phone.
3) yes video can be used as evidence, but not the text messages.

if i were the lawyer of the owner, I would accuse you of theft or robbery.