Re: Heard that one before
1) Nothing. The logs show they are just socket checks.
It is literally, "Are you there? No? Ok."
2) If you're dropping or otherwise blocking the checks, neato. Nobody cares.
If your device is a hardware device, in this case no, it wouldn't help you.
The fact of the matter is that Halifax isn't technically scanning you.
Halifax is providing you with a piece of Javascript code and having you scan yourself. This is indicated by all of the '127.0.0.1' addresses in Moore's screenshots.
There are numerous programs to prevent this, if you so desired.
3) What.