How long are images kept on the CacheCam website?
It depends. If there are a lot of users making image grab requests, then the number of images will increase fairly rapidly, pushing the older images off the end of the list. If you use CacheCam without including a Reply-to address, then it is advisable to come back to cachecam.com soon after your image grabs are complete and download your own copy of the image before they are removed from the Recent Grabs section of the website.