It's not only US domestic travelers that it affects either. I got my first e-cig in around August last year. The same one I have now, just a standard 510.
Your story reminded me of what happened when I was travelling from the UK back to CAN. I had checked in my luggage and was going through security, I had 2 5ml bottles of juice in a clear bag with my perfume (around 30ml) and my hand cream (also a small tube).
They stopped me and asked what the liquid was, I explained and I showed them my e-cig. They then decided that because my perfume was in a bigger bottle (around 65ml I think) that I had to throw all my liquids out or check them in. Apparently although the signs all say "a bottle no larger than 100ml" what the signs meant suddenly is that "all the bottles must add up to 100ml".
We had around 40min left to get to our flight as I hate going in early, so we had no time to go back to check my backpack in. I also asked to see a supervisor and the supervisor was also on lunch (at 3pmish) and there was no way for me to do anything. I tried being reasonable and suggesting I throw out one of the liquids and the hand cream (my husband had more lol), but they insisted I throw out everything - including my bottle of perfume that my step dad had given to me before he passed away.
I was so angry and upset, it was very frustrating, made even more frustrating when I realised I had an umbrella with metal spokes in my backpack that is apparently less dangerous than things like nail clippers.
Sorry about the rant, your story brought it all back