Ok, guys I've been reading the spotting thread in PS2 discussion sub-forum and I've got an idea how it could be done correctly to avoid all possible exploits.
You'll always be able to inform your comrades via VOIP but that method lacks the visual component and we all know that picture is worth a thousand words.
Here is my idea:
WHAT CLASSES SHOULD HAVE IT? Infiltrator and Light Assault only should have this ability.
HOW IT SHOULD BE DONE? When person get in position and presses "spot button" his visual input should be sent to screen of all the comrades in his squad. As soon as spotter starts moving quickly or firing video link should be terminated.
WHAT PROBLEMS ARE AVOIDED? Blind spotting in the dark or through the vegetation. Doesn't not make aiming easy simply informs other of incoming threat. Thus can't be exploited for solo use.
POSSIBLE PROBLEMS? This kind of spotting would actually require good positioning from a spotter to be useful for this comrades (i.e. it would be the best if spotter was up high and had both his mates and incoming enemy in his view). But this could actually be a good thing imo since it would require skill and effort to be useful. If you spotted blindly in the dark your mates would get nothing useful.
Here is a preview how it should look:
(this screen makes no sense; NC guy showing TR spot-cam; it's just an example made from two 1st person screenshots I found)
p.s. please discuss, try to find flaws and point to them, also vote it up if you like the idea.