loads of people's youtube videos/user avatars often have pics of gas masks... even joey adhd had a pic of himself in his sig a while back with (i can only assume) himself in a gas mask... juggernaught love their masks?
People who like dnb also mostly like to blaze. Not everyone, I know, but most people. Ever had a tug on a joint through a gas-mask?! It's like smoking a hands-free bong.....excellent. People who like dnb are also drug-taking, random fuckas. I'm sure there's been more than a few laughs where a group of mates are on shrooms etc, one of them disappears to the toilet for a while, comes back into the room wearing a gas-mask that he/she didn't have on before, and hey presto everyone's laughing at the one fella/lady who is freaking out in the corner thinking he/she is gonna get attacked by a military nutta.
These aren't theories, just logical uses for gas-masks by dnb heads!