Dear Mr./Ms. Part of the Resistance,
To begin, let me thank you for your service. If it weren't for your prowess and expertise, bravery and dedication, genius and sterling morality...
...we might have gotten rid of this asshole by now.
Since you don't have the courage (like so many of your colleagues) to identify yourself, and sound the alarm loud and clear, please keep in mind that the fate of the world is depending on you.
I hope your abilities are as great as your sense of self-importance.