You'll see a lot of this. Establishing blocks in the local networks is
more time consuming than it's worth. Blocks are usually only in place
temporarily while other business practices are carried out; as any good
neighbor tries not to harrass fellow networks. Once decontamination
starts and users are fixed or suspended from service, blocks will
usually be removed and the world goes back to normal.
On the not so bright side, I'm getting a steady stream of port 135
SYNs from my fellow Comcast customers (i.e., presumably on my side
of Comcast's filters), which may mean the horses have mostly already
left the barn.