You can't trademark a letter. Trademarks are extremely narrow and are only meant to apply in circumstances where one organization's symbol could be confused for another. In general I am very anti-intellectual-property, but trademarks are okay in my book. They are basically for consumer protection.
@pruwybn@storksforlegs In the future, everytime you use the letter X, even to text, you will be charged a fee of x amount of cents based on your income.