Ondrej

Rate limit on that one path, in the end. Agent strings lie and addresses rotate, but nobody legitimate needs forty full-size originals a second.

This is how you find out about bandwidth costs, ideally before the invoice rather than after. Mine was an image-heavy site where a single badly behaved crawler was pulling full-size originals in a loop for three weeks.

Nothing in analytics. Nothing in the error logs. Just a bill with an extra digit and a very obvious pattern once I looked at request counts by path.