QUOTE (toturi @ Apr 8 2010, 08:43 PM)

That's the point. By declaring the action as an Infiltration roll, the player is forcing a roll! By the rules, the Perceiving character now has to beat the character's Infiltration success (if any). Immediately Noticeable is applicable if the character simply states he is going to shout at the guards and attract their attention - no argument there, it is a straight threshold test even if he wasn't Immediately Noticeable. But if he is going about it in a stealthy manner, while the specific actions may have adverse effects on his overall actions, it does not mean that he cannot pull it off.
Just because the player stacks the odds against his own character(deliberately or otherwise), it does not mean that the character cannot pull it off.
EDIT: It looks like you Ninja Edited while I was replying, so some of the below may not apply...The problem here is that you cannot be stealthy and continue to shout out craziness... they are mutually exclusive actions...
I am perfectly in my right to say that there is NO WAY for you to be stealthy while running and screaming... so no, no roll is actually forced at all... The player/character is trying to do something that is entirely impossible for him to accomplish, given the situation you described...
Much like trying to say that you can infiltrate stealthily down a completely barren corrider, painted in White and harshly lit with a guard at the other end of the Hallway watching you approach... or are you going to argue that because the character says he is doing it STEALTHILY, he should get a roll? I am sorry, but there are some things that are impossible to accomplish... A Marching Band can hardly remain unseen while playing ... this is essentially what you are trying to allow with the "The character is forcing a roll" argument...
Something that draws attention to itself is not intending to hide (It is drawing attention to itself), and therefore cannot hide...
Here is a good example... one that actually came up in a game within the last month or so...
Our team was infiltrating a highly secure facility... the Team took all of the precautions, and we performed fairly well... unforutnately, teh technomancer rolled pretty badly on his infiltration roll and was spotted not only by the patrolling aerial drones (with Heavy machineguns to boot), but by a team of HTR Goons... instead of trying to get around the corner and break Line of sight to the team, he decided to remain still and trust in his handy dandy Chameleon Suit...
The Goons kept Line of sight, never lost contact and decided that they would fulfill their mandate and shoot the poor technomancer... So 2 of them took a knee, and at a range of about 20 meters, proceeded to aim and then fire their Assault Rifles a Long Narrow Burst each... Now, the GM asked the player if he was sure that he did not want to move, or perform any other action, even though it was pretty obvious to all of us that he had been compromised... he chose to remain still (so no Dodge) and he took the brunt of the attack, which reduced him to overflow damage and the rules for bleeding out... Bad Choice....
The Technomancer's Player used the same logic that you were using, that he should have not been seen, as he was against the wall and that the chameleon suit should have provided sufficient "cover" as to render him unseen... unfortunately, for him, however, the guards never even had to roll beyond their initial perception roll, even though he had stopped moving... their radar systems and tac-net (of which the overhead drone was a part of) had already penetrated his stealth attempts and they were never forced to re-acquire their target... bad luck for him... once he became "Immediately Noticeable", through no fault of his own, he lost the ability to reattempt that stealth (because he refused to take any actions that would have given him a roll, like sliding around the corner of the building)...
This was a valid decision by the GM... there was absolutely no other action the GM could have taken within the confines of the circumstance... In fact, any other decision would have cheapened the experience for the rest of the team. In the end, the character was pulled to cover and stabilized, but it was a learning experience that he would not forget, I am sure...
At the end of the day, the point is that should the GM declare something Impossible, the character needs to find a different approach... If the character still tries to perform the impossible, he should reap the consequences of that action... Actions that are contradictory to each other are doomed to failure from the get go...
I probably rambled on a bit, but oh well, it is getting a bit late anyways and I am feeling a bit loopy... Hopefully I made some sense in there somewhere...
Keep the Faith