I've seen plenty of questionable videos and photographs, both of UFOs and more my field, ghosts, and shock horror - they're never given a look. And if they are *deep breath*...
As far as the topic question goes, I don't think movies have much influence on sightings/experiences at all. Well, perhaps on the attention seekers of the world who crave a spotlight, but for the majority of folk? Nah.
Eyewitnesses can certainly lie even in groups, whether intentionally or not. Humans have that down to a fine art and have done so since we likely started communicating and yet that is a better source of evidence??
Think about how many people spend time actually looking at the sky. Not many. When a movie comes out about aliens zipping around many people are going to look up. Due to not being aware of what is 'up there' they likely will see things they are not used to. Some of them are going to see 'UFO's and some of them are going to draw the conclusion, often mistakenly, that they are alien ships when it could be completely prosaic.
I do not automatically discount accounts of UFO sightings. It is just that an account is just that, an account. Nothing about a story can be verified without additional evidence to back it up.