See processes which use device

I have this (hopefully) irrational fear someone might hijack my webcam, especially since some of my colleagues started to put some tape around theirs.

For some reason I am sometimes not able to access /dev/video0 while using skype. A while ago I made the experience that only one process can access my camera.

How can I find out which process (if?) is currently using my webcam? Also how can I unmount and re-mount the webcam?

Thank you


$ lsof /dev/video0

Should tell you which processes are accessing the device, if any.