Been having a lot of problems with attempted comment spam over the past 6 months or so, to the extent that I have had to upgrade my hosting package to cope with the extra bandwidth they are soaking up! Usual bandwidth in the past was around 500MB per month, it has gone beyond 5GB a month now.
95% of the bandwidth is used up by the image files that get downloaded every time they open a page. Although a handful of images are oversized, most of them have been re-sized before upload so are around 200-300K. I use the "full-size" option in my posts because it looks better in my opinion. But since there are several images per post I end up with over 1MB bandwidth from a typical visit.
I have tried a couple of caching plugins but they don't appear to be able to do anything about the images (unless I have misunderstood them).
So what I am looking for is either...
1) A way of stopping the images being served to suspicious IPs
2) A way of significantly decreasing the size of the images on the site. The WordPress generated thumbnails are not really any smaller than my own resized files.
Any solutions out there?