Last night at midnight local time I started an experiment to see if I can get these images back into the SERPs and at the same time stop the hotlinkers and bandwidth stealers.
Using CPanel's AwStats "Links from an external page (other web sites except search engines) - Full list" it's possible to see the domain linking to you and if you already have some names enabled in CPanel's IP Deny Manager in "Security", go to AwStats 404 and you will see all the domains you have denied.
All the 404 domains I did not have in my IP Deny list I have now added. The good thing about this is concentrate on the most problematic domain and deny as many IPs as you can then when you go to do another site all the names are already listed, the only pain is that you have to add them manually one at a time, but hey, it only takes a few minutes for each site.
I did about 20 sites last night and disabled hotlink protection on each of them.
I'll see what transpires over the next few days and keep you informed, if it goes ballistic before then it's easy enough to enable Hotlink Protection again.