Surely you know they are fake. Not getting rid of them will just invite others to post more nude pictures of other women and before you know it there goes the forum.
you could also look at placing a disclaimer notice for your protection on the legal side. you could mention that if someone posts something on the forum you have 10 days to get in touch with the user and remove it. This would be beneficial if for instance some1 posted an image that was copyrighted and the respectful owner got in contact with you with you with a court order. This dissimilar or possibly terms&conditions can secure you in this instance. :-)
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