When I worked at Mozilla, most stuff was open, but I still couldn't talk about stuff publicly because I wasn't a spokesperson for Mozilla. Same at OpenDNS/Cisco, or at Fastly, and now at Amazon. Lots of stuff I can talk about, but I generally avoid threads and comments about Amazon, or if I do, it's strictly to reference public documentation, public releases, or that sort of thing.

It's easier to simply not participate, link a document, or say no comment than it is to cross reference what I might say against what's public, and what's not.