[hayek]

Per the recent errata, “The IC in a host and the host itself share marks, so if one IC program marks, they all do, and so does the host itself.”

They've definitely clarified that Marks are shared 'offensively' (and I think since they removed the old sentence, they're trying to say that Marks aren't shared 'defensively', i.e. a Hacker must mark each IC and/or the Host separately). Is this everyone else's take?

Separate question: IC and Hosts share marks, do you think this means a security spider shares marks as well? Or do they have to mark a hacker separately? p. 360 says Spiders are considered owners and/or administrators of the entire system and can launch/shut down IC. I get the impression from all this that they would share marks with the Host/IC, but what does everyone else think?

[Namikaze]

This is purely speculation on my part, because until we get something official it'll be impossible to know for certain.

They've definitely clarified that Marks are shared 'offensively' (and I think since they removed the old sentence, they're trying to say that Marks aren't shared 'defensively', i.e. a Hacker must mark each IC and/or the Host separately). Is this everyone else's take?

This is my take as well.  I think the idea was to make it so that you can't mark IC and then suddenly become the administrator of the host.

Separate question: IC and Hosts share marks, do you think this means a security spider shares marks as well? Or do they have to mark a hacker separately? p. 360 says Spiders are considered owners and/or administrators of the entire system and can launch/shut down IC. I get the impression from all this that they would share marks with the Host/IC, but what does everyone else think?

This is a little trickier.  Presumably a spider uses a deck, which would be a different interface from the rest of the host.  It gives them a little more autonomy as well, but they sacrifice that autonomy for the inability to use the marks built up by the host's IC.  However, if a terminal was involved then it would likely be a slave to the host and therefore share in the host's marks.  Terminals have no rules in SR5, but I'm hoping that changes with Data Trails.

[Xenon]

As I see it you fight the host.
The host can load different skill sets.
The eyes of the host is the Patrol IC.
The firearm of the host is the Killer IC.

The Patrol IC and the Killer IC are not entities of their own.
They are extentions of the host.

The host first have to spot her target with her Patrol IC before she can use her Killer IC to attack it.

A spider is something totally different.
The spider have eyes of his own.
The spider got attack software of his own.

The host can inform a spider that there is an intruder
The spider, acting as the owner, can tell the host to launch IC and search for an intruder
But a host can not automatically target an intruder that only the spider located