I guess our upstream provider is a nobody because they have lots of small
sub-allocated blocks less than a /24 that they route to different member
What is the point of blocking a /24 on the basis of a /32 if the ISP manages
dozens of other /24 or larger blocks? If you're going to do it, block *all*
the IPs associated to the 'bad' ISP. Then at least you're consistent,
otherwise expanding to a /24 is just a half (or 1%) job or laziness.