>I thought trademarks were based on market and context?
They are.
Monster Energy holds trademark SN 97273630,[0] which covers:
"Downloadable virtual goods in the field of beverages, food, supplements, sports, gaming, music, and apparel"
...among many other things.
[0] (basic search for 97273630, change "field" dropdown to serial number) https://www.uspto.gov/trademarks/search