I know usually they cannot but is that only if they are in their starting area?

Thanos places your two highest pieces next to him on turn one, can his team then attack, since you're not in your start zone?

2011 rulebook page 7:
FIRST-ROUND IMMUNITY
During the first round of the game, characters that have not been given an action, placed, or moved can not be targeted by opposing characters, knocked back, attacked, or damaged, unless a game effect that does so specifically states that it occurs at the beginning of the game.

Thanos' power places the characters, so they are no longer protected by FRI.

So once they are placed, why wouldn't they still be protected

Because "...characters that have not been given an action, placed, or moved can not be targeted by opposing characters,"

Since Thanos PLACED them near him using his SP, they lose the immunity beacuse they have been placed.

And they are also immune to the SP even when they are in the Starting area at the beginning of the game cause Thanos' SP does NOT target them.

Doesnt this loophole the base Heroclix rules regarding first turn immunity?

How so? The rules seem to let this be totally legal.

The main problem is its just about as devestating on the second turn as it is on the first.

Of course it is a loop hole. But odds are the sp was probably developed with a 300 or 400 point build total in mind. In the case of the 300 he does not have the sp on his first click. In the case of the 400 you only have 50 points left over for another character which probably wouldnt do too much harm. And since the issue you have is the placing of pieces who have not been given an action, it might actually be a bad idea to use first turn.

Thanos would be given an action to place the two highest point figures with no action tokens right next to him. They will be able to attack him the very next turn. I think the sp is great in high point games in many cases but not til 2nd or third turn. I was able to pull both a stealthed loki and doom away from tons of wildcard mastermind fodder (totally destroyed my opponents entire strategy). But in no way is it game breaking at the standard 300 or even 400 point tourney builds. My two cents which probably don't belong in the rules forum