TOPIC:

You have to have a disclaimer on your site clearing yourself from copyright claims and stating the ownership and responsibility is with the one who posts the even and grants you permission to use the image. Still, as a site owner, you have to check regularly if there are images uploaded that are copyright protected.
If someone else steals an image from your site, the owner of the image (the user) can claim copyright.

What about the cleanup images in the housekeeping?

It is wise to add a field to JEM where one can add the name of the photographer/copyright holder, which should be displayed below the image.

@Bluefox You are using one of the 10 custom fields for this? How did you create an upload field from the textfield? And why not hook into the upload of the image?

@Bluefox You are using one of the 10 custom fields for this? How did you create an upload field from the textfield? And why not hook into the upload of the image?

Nope, am not using the custom fields. Did use the Blueimp-script and additional info can be intered into fields (something like attachment fields). Am also not using current JEM2.x, am using a modified version based upon the "old" JEM3.x.

Maybe, to add a bit to the thinking process:

Is it possible to crop images after upload, but before they are stored?

I fell in love with the way Eventbrite does this. In JEM there is often a discrepancy between the event image that you want to display in detail view and the one you want in list view. Mostly the last one needs to be in a fixed px x px format to keep the list view clean and sharp.