Can I force my ex to delete nude photos legally?

In the old days, pictures were taken on film and printed and those physical things could be the subject of a property dispute. Now, the information is digital and while similar in many ways to their old physical analogues, there are subtle legal differences. If you took the photos, of yourself, with your own camera, then did you give your ex permission to use your camera, view its contents, etc.? Are you of legal age? If not, and since you did not grant use permission, then you can threaten to call the state attorney and report the incidence of theft and the threat of use the photos without your permission. That's the criminal side of it - and the cheapest way for you to make an impression on him. On the civil side, his taking the photos and publishing them may be an intrusion into your seclusion or privacy, and that may be actionable by civil process, but that costs time and money. Such actions are usually preceded by a letter to cease and desist the activity or else an injunction and/or a law suit may follow. Such a letter from a law firm may also cause your ex to take notice and discontinue his threats. However, "forcing" some one to do something is hardly ever legal. Threatening to act in conformance with the law in retaliation to his threats are alright to try, but I cannot think of much else in this circumstance. Save all communications with him and date and time stamp everything. Maybe some other lawyers here may have additional useful ideas. Good luck.