First of all, whether there is a fingerprint on the loan guarantee is not a sign of whether the guarantee is established or not. As long as he signs it voluntarily, the guarantee is valid. Moreover, the borrower is now detained for economic cases and may be sentenced or his property confiscated. In this way, your friend will suffer.

But now you can ask your friend to go to the police to explain the situation and claim the creditor's rights, and now the lender should also know the fact that the borrower is detained, so the lender's friend can also tell the lender about the situation and let the lender respond positively, so that he can pay back the money as soon as possible and reduce the loss.

Personal information of ID card belongs to personal privacy. Privacy refers to a kind of personality right that natural persons enjoy the peace of private life and the privacy of private information is protected according to law, and will not be illegally violated, known, collected, used and disclosed by others. Moreover, the right subject has the right to decide to what extent others can interfere in their private lives, whether they can disclose their privacy to others, and the scope and extent of disclosure. As a basic right of personality, the right of privacy refers to the right of citizens to "enjoy the peace of private life and the protection of private information according to law, and not be illegally harassed, informed, searched, used and made public by others".