I recently flew with United Airlines and I used their free messaging wi-fi plan.
I could text my friends on Whatsapp, but I could not send (nor receive) multimedia content like images, videos or audio clips.
I'm wondering how this works and whether it is secure. Since they're able to selectively block traffic, I'm assuming that this blocking goes beyond a simple white-listing. Somehow they managed to inspect my traffic and block byte-heavy content.
As far as I know Whatsapp has end-to-end encryption, so honestly I'm at my wits' end regarding how this works. Would they be able to read my texts? My online searches haven't helped so far.