Right. Ok. I was reading through this, and I noticed that a Bungie.net moderator posted this in relation to the BOBs:
Before proceeding any further, you must take the oath of the vidmaster:
"I pledge to punch all switches, to never shoot where I could use grenades, to admit the existence of no level except Total Carnage, to never use Caps Lock as my "run" key and to never, ever leave a single Bob alive."
Although it's from Marathon, it also seems to apply equally well to Reach. This seems to me quite obvious that these are instructions for what you have to do to potentially unlock this helmet. You have to make your way through the Campaign
"punch[ing] all switches" (collecting all data pads or switches or both)
"never shoot[ing] where I could use grenades" (never firing a single shot, or at least not until all your grenades have been used - looking up what it meant in Marathon will probably make this clearer),
on "Total Carnage" difficulty (this one is a bit ambiguous - it could be Legendary, LASO or LAASO),
"never use[ing] Caps Lock as my run key" (possibly never using Sprint, or never using a certain control scheme? Again, reference to the original Marathon will make this clearer)
and "never, ever leav[ing] a single Bob alive" (self-explanatory).
Also, it seems like Bungie keeps trying to bump our interest in this. We were convinced that there was no Bob on New Alexandria - bam, Golden Tree City. We thought there were no more easter eggs - pretty convincing pics of the Defiant helmet come out, NOT to say "this is coming with Defiant" but just to show that there were still things to discover. And finally, when interest in the Bobs seems to be flagging, we get a bunch of "Find the Bob" challenges at the same time. The Bobs aren't there for the challenges; the challenges are there for the Bobs. They are trying to raise awareness of their existence in the community. BUNGIE WANTS THIS TO BE FOUND.
On a side note, I think I saw a thread claiming that showing that pic on the XBL marketplace was false advertising, but Bungie know what they're doing. It's not false advertising because getting that helmet is and always has been possible.
*thread saved*