In the MiTS description of possessing metamagic:

"Riggers and Deckers: Characters who are rigging and decking may be possessed if they are also astrally active and defeated in astral combat; once possessed, they are immediately dumped from their icon or vehicle. The possessing initiate may attempt to rig or deck, if so inclined."

My question is this: If the rigger/decker is dumped, how does the possessor have access to the matrix or the vehicle/drone deck?

How do you interpret this?

They get dumped, and then the possessor can go right back into the system. It just means you don't get to inherit the current Matrix login and retains a level of consistency between that and the rigging.

...The magician is possessing the decker/rigger's body. They plug the jack back in, hit power on the deck, and go for a little Matrix run.

"Hey kids, I'm not really this body's proper owner! So I don't give a frag if the black IC kills it...just keep me away from that psychotropic stuff. Don't know what it could do to me, but I don't want to take the chance."

Ah, thanks, for some reason I was under the mistaken impression that the matrix/rigging connection wasn't severed and the dump would affect the possessed after the possesor dismounted, as per the astral combat damage taken during the possessing combat test.

Does anyone else see what I am saying? Could it be argued that way do you think?

If the decker/rigger has taken enough damage to render them unconscious, yeah that would put a sore spot on decking and/or rigging.

yeah, in ASIST-based rigging or decking, it'd be insane to not have a safety override system that ends your connection if it detects unconsciousness.

though, note: the rigger/decker should be taking dumpshock, along with the damage from astral combat. that means they'll probably be physically injured to some degree.

Note, also, the great unlikelihood of finding an astrally-active decker unless they happen to be a ghoul, an Awakened deepweed addict, or a changeling with the Dual-Natured trait. Anyone capable of decking and astrally perceiving voluntarily would be insanely foolish to do both at the same time, and most every other intelligent dual-natured creature like Shapeshifters and Vampires can't have a datajack so they'd be going in on tortoise mode (thus no need to worry about dumpshock).

But yeah, blah blah blah, this isn't a scenario you're likely to encounter unless a GM goes out of their way to introduce the situation into a game. Possession alone is rare enough as it is.

They could be in a spontaneously-appearing astral rift, or be targeted unwillingly by a free spirit's astral gateway power.

That would pretty much fall into the whole "...goes out of their way to introduce the situation into a game..." bit.

True.

Well it could always be an unintended consequence.

1) Player binds/makes friends with free spirit.
2) Mage wants to deck, so asks/forces free spirit to use astral gateway on random person with datajack.
3) Mage then posesses random person, then decks using his body instead of his own.

Deepweed + DMSO in any viable delivery method. Splash grenade, capsule round, super squirt, even a Deepweed smoke grenade should work.

It is the classic answer to the question "how can two magicians and a guy with an ELD-AR take out an entire swat team?"

Pumping massive ammounts of deepweed smoke through a ventalization system and then having the magician possess the building's Security Rigger would be a great way to gain control of a secure facility. Of course, you would need enough Deepweed to potentially turn the run into a Cheech and Chong movie.

Edit: Darn, I missed the Magically Active part in the description of deepweed. This makes the tactic less effective.