Like any other brand name used in film, Web, theatrical production etc. the answer is easy....and expensive....usually.
Many occasions we have needed specific brand police uniforms. Some forces we have a great relationship with, and authorization is simply sending them a script. Depending on the budget, some ask for a fee to use their intellectual properties, while others will allow smaller budget at little to no fee.
Every brand, name, police force, etc. owns the image to uniforms, logos, print material etc.
Even making a news cast using FOX. you would have to contact there intellectual properties division (and all big brand have an office that deals with movies and public events). They will most definitely want to see the script, the actors, and who the production team is. In all cases, this will take a few weeks.
Something as small as seeing a specific brand on a video without consent can cost a large legal bill, and a large law suite, and possibly have the project pulled. In many large feature films, when an actor is walking through a grocery store, either the product names are turned away, or the shelves are stocked with in heard of brands (these are movie look alike packages) because it would cost a fortune to get every single brand approved in a store.
If you can see the name, it has been paid for, or approved in writing.
We have our own 9 beer labels for bars, that we designed for film projects.