I work for an international organization that is organizing a conference that will have around 3,000 people in attendance. To illustrate certain points in our presentation, we wanted to include trailers for certain movies. However, the studios told us that we weren't allowed to use them. Thus, we would like to show the official poster of the movie on our powerpoint presentation. This is a non-commercial conference about work safety and prevention.
Would we get into trouble for using the movie posters?