Just play a game with my friends this weekend and this question came up. If I am in the middle of a horde smashing things with my powerfist, and my friend cats smite on one guy in the horde, do i get hit with the smite attack? my group is split on this decision, but as written it seems like it only targets enemies, at leat thats what is sounds like to me. So can this smite attack or other targeted powers for thatmatter hurt allies?

I've interpreted it as Smite can target someone in the horde (but still acts like an AOE, centered on that target), and if your battle-brother is within PR metres of that specific target in the horde, then he'd also get hit. However, as Smite is modified like a BS test, you'd get a -20 penalty for "shooting into melee" (the horde is in close combat with a battle-brother), which you could say is the difficulty trying to aim at a specific target out of reach of your battle-brother.

Still, some mean-spirited GM could deem it hitting the battle-brother if the horde isn't big enough, but I doubt that even rarely being the case (atleast not at lower PR levels when the AOE is still small).

In other words, I'd treat it just like targeting a non-horde which is close enough to a battle-brother, although it's much easier to know if it hits someone else or not due to it being much easier to estimate range.

Page 360 describes what the attack does to the horde:

Psy Rating +1d10 hits

Personally I'd rule on the fly whether the brother is hit as well based on where he was in the horde when it was hit. If the horde was small or he was close to the point of attack, I'd treat it similar to the stray shot autofire rule and apply the hits across the horde and potentially hitting the brother. You're not doing a single hit into the horde like you would from say a sniper rifle, so the brother has a chance to be hit.

I'd still also inflict the -20 for shooting into hand to hand to the focus power test, as indicated on the smite rules.