Can an employer or co-worker touch or remove your personal belongings from your desk ?

My 2 other co-workers were asked to stay after hrs. to rearrange our desks, I was not told about this or ask to stay. In doing this, they removed all my personal and work related things out of my desk, gave my desk to one of my co-workers and gave me a desk that was not in as good shape. They then arranged their desks to face each other and have the ability to see the office surroundings and turned my desk to face the wall, which left me without the ability to see them or any of my surrounds. This is what I discovered as I walked in for my day.I don't understand why they felt they had the right to touch and remove my personal belonging just so another co-worker could have my desk and why I was turned to face the wall. My manager and her boss where both there and allowed this. I feel this whole situation was unfair and I am very upset. I am not a problem employee and have been with this company 6 yrs. which is longer than any of my co-workers. I can not understand why this was done to me and if they even have that right to do that with my things without my knowlege or consent. Please let me know your thoughts. Thanks