All perfect praise be to Allaah, The Lord of the Worlds. I testify that there is none worthy of worship except Allaah, and that Muhammad is His slave and Messenger.
There is a difference of opinion among the contemporary scholars about the ruling of photographic pictures; some permitted it and some prohibited it. However, in order to be on the safe side and avoid the difference of opinion, it is better to avoid photographic pictures; for more benefit, please refer to Fatwa 87765.
Therefore, you should ask whomever you are sure or you predominantly think that he/she has a picture of you to tear it off or give it to you to tear it off. Rather, you should endeavor to do so if your picture was taken while exposing your ‘Awrah (parts of the body that must be covered in Islam) or that you know that it will fall in the hands of a man who is not permitted to look at it because he is a non-Mahram to you.
However, if you are just doubting whether or not someone has a picture of you, then you should not worry about this.
We gave you the above answer on the basis that those friends are female friends, but if you mean male friends, then it is not permissible for a Muslim woman to have a friendly relationship with a non-Mahram man or to give him her picture. For more benefit, please refer to Fatwa 81356.
Allaah Knows best.