I'm not sure if this is a bug or not, but someone tossed a bunch of spheres at me and they all stacked until my defense was abysmally low.

Is it really the intention for the artifact to be able to do so?

The wiki documentation doesn't say that it is possible.

If the admins want me to say who's been doing so, PM me about it...

it's been like that since I could remember.

I never use em myself. Slows down my blowing up other ships so I never know.

It is odd that it's the only effect that is really stackable that you can toss on another person. I have seen the Krionus Virus Trap be stacked. Just not any other one.

Disarming bombs can be stacked, and probably flares and clouders, as well.

yep, what chiaroscuro said. if these artis did not stack, there is very little that a much lower-ranked player can do in response to a situation like a planet theft.

for example, i had someone steal one of my arti planets. i didn't have much energy, so i just flared him until i could zero out his 5 hacks.

for some reason he took offense to this (despite having looted the planet) and came back to disable me. since he was 4x my rank, i waited another day to resupply on tm's and picked up a couple of tactical remods. burned up the rest of my flares and clouders to hack him again, hit him with the remods, then still had to dump a bunch of disarming bombs to get him in range of my guns.