$wgAutoblockExpiry might be unrealistically low for today's needs.
After gerrit change 23924, twn /seems/ to have experienced way less problems https://translatewiki.net/w/i.php?title=Special:Log/block&dir=prev&offset=20111230070847&type=block
Autoblock is an effective measure, easier that CU+block and more flexible than rangeblocks, to reduce usage of bad IPs, so increasing it could be useful, especially until bug 17929 is fixed; cf. bug 25305.
This bug is just for tracking, to avoid forgetting this possibility, which has some big drawbacks on some wikis which have e.g.:
- legitimate users from dynamic IPs quickly "polluted" by vandals/spammers changing them continuously;
- sysops not aware of how autoblock works.