I noticed this same thing the other day. They're blurring the images when people exceed a certain bandwidth allotment. At first I thought I was just looking at some very out-of-focus photos, but then I saw them on forums everywhere.
HSM is using the same forum software that we are. Here's the image caching plugin I'm using: https://www.vbulletin.org/forum/showthread.php?t=253309 . And then I modified the script to store the cached images both on our server and in a geo-distant Amazon S3 bucket. This gives us multiple backups in different locations, and the images serve faster and more flexibly from the Amazon S3 bucket. I'm happy to share my code modifications with their admin. What he can do is wait until the first of the month, or whenever the Photobucket periodic bandwidth allotment for images is reset, and the images display correctly. Then he can run the caching program to quickly retrieve all of the images.