It's a shared Web hosting account. I have no access to such Apache directives, but the logs are accumulating and they are increasingly eating my quota (but I can't remove them, either). And the attacks were recorded from hundreds of hosts thus far with nearly no repeat, although I believe the attacks are coordinated by one party from behind, as shown by an identical cryptographic signature for all attacks. Apart from Apache logs, some logs are written by my site scripts that I can provision, but unless the source can be stopped those requests are still dragging down the server and leaving me lots of logs.

As for abuse report, do netblock owners typically entertain them?