Security can mean security against hackers, but it can also mean security against revealing classified information. Classified information about weapons systems (e.g. performance characteristics) is inherently embedded into the code running on those systems, and therefore shouldn’t be open sourced.

Source: used to write classified code

I think it’s generally because glass bottles can let light hit the beer, and hops are photosensitive (light-struck beer will have a skunky aroma and taste). Brown bottles are the best at blocking light. Clear and green bottles are pretty bad. Cans obviously block all light.

I think most of the time, brown bottles are just fine, but the judges probably have a bit of bias here on their preferences.