Stifleing Piledriver?

[Harlequin]

When Pile Driver attacks, can his +2/+0 (per gob) be stifled?   I would say yes.  My questions are:

-Is it all ONE triggered ability? or are there [N] separate +2/+0 triggers go on the stack (where N=#of gobs)?

-Does Protection from Blue apply to the triggered ability generated by Piledriver?

[49 Cents]

Piledriver had protection from blue. Good luck targeting him!

[Cross]

Piledriver's ability is one ability. Stifle doesn't target the source, but rather the ability itself, so protection is not an issue.

[ashiXIII]

What Cross said.

[LotusHead]

Oracle text: Protection from blue
Whenever Goblin Piledriver attacks, it gets +2/+0 until end of turn for each other attacking Goblin.

The triggered ability happens once (if it resolves), and that's when Goblin Piledriver attacks.

Basically, the Trigger goes onto the stack, far away from the protection from blue ability, and from there, you respond by Playing Stifle on the Trigger that is on the stack. Stfile pwns Trigger (assuming no red=blast, chalice for 1, etc) and combat continues as normal (with Piledriver being less scary)

Stifle the ability, and it doesn't get any pump (The trigger doesn't trigger).  If it somehow got to attack a 2nd time, Piledriver would re-trigger.