Strange abuse attempts, spam-bots

It has come to our attention that quite a few sites owners abuse our service by requesting "showimage.php" script from their sites and thus unnecessarily spending our bandwidth.

It is still unclear if that is an intentional abuse, or those guys simply do not realise that "showimage.php" script DOES NOT check pagerank, but it only serves internal images for site internal purposes. Anyway, it has been blocked from outside access.

We also had to block few major ISPs due to constant abuse by spam-bots from their networks. Now we are considering to publish a blacklist - a list of spam-bot friendly networks.