Thanks, everyone, for the opinions!
Honestly, taking a photo in this situation was just instinct for me. No malice intended. No intention of posting this publicly on Twitter. Just a photo of an experience I had at the airport that I wanted to share with some of my friends on Facebook. In retrospect, I can see how this may be interpretted as rude. This, however, is probably deserving a larger discussion about the realities of the world today. Once confronted and threatened, however, I very quickly realized that he'd interpretted it as disrespectful, and did what I could to de-escalate the situation.
Anyway, I did let United know (without his name or photo) -- not that I was being asked to check my bag. He was just doing his job, and I'm ok with that. It's the threats that I have a problem with. Had he come over, and calmly asked that I delete his photo, something along the lines of: "Sir, United has a policy against taking photos of United employees at the gate. I'd really appreciate it if you'd remove the photo," I would have been a bit more understanding.
This was United's response:
Thank you for contacting us regarding your recent experience, specifically your interaction with my co-worker.
Our goal is to be “predictable”, “the solution”, “gracious” and “the brand”. Please know that the treatment you described is no more acceptable to us than it is to you.
Direct customer feedback about our products and services is so important in helping us to improve.
Our ability to communicate professionally with our customers is a key component of our brand, being Flyer Friendly. A number of tools and processes are being applied this year that will substantively address these goals. We are working to improve customer service, including investing in a comprehensive training course for frontline employees. We are consistently aligning service standards of 80,000 professional women and men around our company.
United Airlines strives to provide customers with a safe and pleasant travel experience. The use of any device for photography or audio and/or video recording is permitted only for capturing personal events. Any photography or recording of other customers or airline personnel without their express prior consent is strictly prohibited. Any photography (still or video) or recording (audio or video) of airline procedures or aircraft equipment is strictly prohibited, except to the extent prior approval has been specifically granted by United Airlines. This policy is not a contract and does not create any legal rights or obligations.
We hope to welcome you aboard another flight in the near future, and thereby have the opportunity to win back your trust. Our goal is to create the world’s most Flyer Friendly airline. We still have room for improvement, but that’s the direction we’re headed.
We appreciate your business as a Premier Gold MileagePlus member and thank you for flying the friendly skies.