Originally Posted by wharvey

The way to resolve it is to buy the seat you want blocked.

I do not believe you have a "right" to an extra seat that you did not pay for... you are trying to do the same thing as the person who moved... trying to improve your seating arrangment.

What action did you expect the FA to take? To tell the person to move since you want an extra seat you did not pay for?

We all love having extra seats beside us... but we cannot go as far as expecting it if we did not pay for it.

Even as an elite member on UA, seat blocking happens in advance. But there is no guarantee of it still being blocked on day of flight. People can - and often - move during the pre flight, often at the FA's request.