I used a trademark in a domain in my very naive and younger self, one of the first domains I registered I think and ran it for about 5 years way back when, grew it to around 15k UV a day, 3-5million PV a month, had causal discussions with the entity's director and marketing directors it was infringing, I even offered them to buy the site at one point.
Not at any point did they pursue me other than to request I changed our logo to not resemble the official logo in any shape or form.............but that didnt mean I was in the right and it doesn't mean they couldn't have taken it from me in an instant given their size.
I did end up changing the domain and redirecting the old one while I still had the chance to retain authority and traffic....once I had learned the how risky it was and how stupid I was, I consider myself lucky. I'm pretty sure if it had been the director previous to the current one in charge, I would have been on the chopping block and the site would be no more.
You can get away with it, but it doesn't mean you are above the trademark. Not knowing, or being too naive isn't an excuse.