This story takes place back in the early 1970s. At the time, about ninety percent of all of the LSD on the East Coast had been traced back to one laboratory- Bexley Hall at the Massachusetts Institute of Technology. Needless to say, the FBI wasn't terribly happy about this, and so they decided to make a raid. They called up the President of MIT, and told him that they would be arriving on such-and-such a day at such-and-such a time, and to make sure that none of the students knew about it in advance. And the President thought about this for a little while, and then called up the Bexley Hall Housemaster and told him the same thing.
On the day of the raid, the FBI pulled up in front of the dorm in their black Lincoln Towncars, and saw to their surprise a giant banner strung over the Bexley Hall courtyard reading "Welcome FBI." Now, at this point, the agents were pretty sure that the raid was going to be pointless, but they got out of their cars anyway and walked into the courtyard. There, they found a nice painted set of footprints with a sign next to them: "Follow the footprints to the room you're looking for."
And the agents sighed, and shrugged, and followed the footprints into the dormitory,and up a flight of stairs. And around a corner, and down a flight of stairs, and down a hallway, and through a room, and up a flight of stairs and down two flights of stairs and through another doorway and around another corner and so on and so forth until finally they wound up in front of a door in the basement. Now, by this point the agents were starting to feel a little frustrated, and were not at all surprised to discover that the door they'd come all this way searching for was locked.
One of the agents got ready to ram down the door with his shoulder, and was just preparing to run at it when a door opened right next to them, and a sleepy student handed them a key. The disappointed agent tried the key in the lock, and sure enough, the door opened. Inside was a large room, empty of furniture, and freshly whitewashed. And there, in the center of the room, sat a plate of milk and cookies.
Now, at this point, the FBI agents were furious. These MIT students had been toying with them, and they were darn well going to make sure that they learned their lesson. So the agents started to take the place apart from the top down looking for drugs. They tore open sofa cushions, knocked over furniture, looking for any evidence they could find.
Finally, they made their way to the basement, and started taking up floorboards. And, sure enough, there they found a great chest, wrapped all around in inch-thick chains, and covered in padlocks. "Aha!" thought the agents. "Now we've got them!" So they called in the welding tools and the giant metal clippers, and they cut through the dozens of chains, and broke open the lock. They flung open the chest, and sitting inside were three marijuana seeds—exactly one fewer than the minimum needed for a conviction.
The FBI never came back to Bexley Hall. The LSD lab did shut down on its own, and moved off to California somewhere, but by then the Feds had learned that MIT students can take care of themselves.