A straight clean-cut mayors phone is found by paparazzi. The mayor has nude photos on the phone. The mayor accidentally left the phone un-locked. The paparatazzi is ready to sell the photos, however, we have a catch.

Who is the protagonist? The mayor or the paparazzo? That's your first hurdle you want to clear up.

What is the catch?
Is the nude model in the pictures the paparazzo's mum?
Are the pictures of somebody that the paparazzo a relationship with?
Are they pictures of the U.S. president's wife?

You are describing a situation, not a story.

A logline gives a quick glimpse of story.

If you would like to improve this logline, I would start be giving us a lead character. Give us a goal for that character then give us something standing in the way.

Is the mayor the lead character? Or is the paparazzi? It sounds like the Paparazzi are the one initiating the action.

Let's try it this way (With the mayor as the lead character)

"After his phone is stolen by the paparazzi, a mayor with a clean cut image must retrieve it, and the illicit photos it contains, before his career is ruined."

Hope that helps, good luck with this!!