To touch or not to touch: Patron devices in the library

It has been a week since our first Edge Initiative benchmark webinar, but I keep thinking about the questions and ideas that were shared. In the webinar, we were discussing Benchmark 1:

Library staff and volunteers provide assistance and training with the goal of increasing the level of digital literacy in the community. More specifically, we were discussing e-readers and providing digital literacy training. Many tips were shared, but an interesting question was raised: "What is your library's policy about touching patron-owned devices?"

This is not an issue that is solely related to e-readers. For years now, libraries have been working to establish policies and procedures related to patron-owned devices (see Recipes for a 5-Star Library: How much help should you provide laptop patrons?). During the webinar, participants shared a range of policies and perspectives:

Disclaimer:  The library’s intent is to help people learn to use their devices.  The library cannot assume responsibility for devices that are not working and cannot fix devices"

Pretty much is based on patron's preferences. Some are okay to touch their ereaders and some are not" to "One library I worked with made a point of always asking for permission to touch the device."

Where does your library stand on touching patron-owned devices? Do you have a policy? Have any of you ever had an experience in which assisting with a patron-owned device backfired? During the webinar, guest speaker Diana Weaver emphasized that personal responsibility for learning is the guiding philosophy behind the training and assistance they provide at her library. How does that impact interactions?