A quick trick that I found out the hard way and thought I would come share.
I had just logged on at my hearth point in Stormwind, when a level 85 zoned in on top of me. A second later I got hit by a spell and died. So, did I quick bit of research on the spell and here is what I found:
The spell Seeking Shadows is cast by Faceless Shadow Weaver in Hour of Twilight. If it hits you, and you leave party and zone out within 4 seconds. The spell should detonate killing all low level characters in a small radius of you.
I haven't had a chance to properly test this and am mainly working off the fact I got killed by this spell in Stormwind.