The first thing that comes to mind is to avoid discussions of "right" and "wrong" for a while. Stick to the idea that it is "not nice" or "against the rules", and try to force her to put things back within a few seconds after picking them up.

If you create a habit of putting things back, you can build on that, rather than trying to explain morality in a single lesson.

Try to reward her for putting things back, (obviously with something other than the desired object.) If done right, the reward can become more motivating than the object.

There is something called "magpie syndrome" as well. Some kids just want to hold things that are shiny, and they will take objects as part of the craving. You might have to develop your own collection of shiny electronics, and carry them around for a while.

This has become a big problem with my daughter as well. It has always been an issue of "stealing" but she has especially been doing it at school with food. Her teacher asked me to please talk to her about it. Every day it's SOMETHING.