first as the dog on four legs, then two, then the red baron, and then the Cool Snoopy. However, these trademarks appear to be on the likeness and not the name.
Interestingly, I was able to find information on the trade mark for the word Snoopy. It was filed in 2011 and approved in 2018, if I am reading everything correctly. First use is stated as 1984 in the filing. But, my research is that it first appeared in a comic in 1950.
There are fair use laws that apply to Trademarks. However, they are much more limited than those for copyrights. So, again, if you really want to use Snoopy Halloween, you should consult an attorney.
FYI under copyright fair use, you are allowed to use the name to ask questions, answer questions, create parodies, etc. Even using trademarked words to ask questions is legal. The purpose of trademarks and copyrights are to protect the works in question, not to stifle free speech.
The daughter of a friend of mine had the same problem. She bought one of those personal alarms that make a loud “scream” when you pull the 2 sides away from each other. She taped the personal alarm to the bottom of the drawer her roommate was most likely to get into, and the other end of the alarm to the back of the cabinet the drawer was in.
She told several friends in her dorm about it, so when her roommate pulled the drawer out to snoop, the alarm started screeching and announced to everybody on the whole dorm floor that the drawer had been opened. This allerted my friend’s dorm friends to immediately come rushing to “help” with the situation, bursting into the dorm room and catching the roommate snooping. They made nasty comments about snooping. AND, everybody on their floor in the dorm kept an eye out for her after that which made her uncomfortable.
She was so embarrassed that she ‘d been caught, she apologized to my friend’s daughter and apparently learned her lesson and stopped snooping.
If you’re certain your roommate is going through your stuff or intolerably looking into your life/plans, you’re not overreacting. Worst case scenario, Snoopy Halloween you need a new roommate. But before jumping to conclusions, I would advise for you to stop thinking about whether you’re overreacting (which will eventually make you paranoid) and just tell them that their actions are making you uncomfortable. They can’t exactly get out of the situation if you confront the problem head on. If you can’t work something out, worst case scenario ensues.