For security reasons, when the President of the United States travels, he has a tightly regulated toilet schedule. He is supposed to exclusively use a specially designed portable toilet that is moved around with him, and the waste is kept and brought back to U.S. soil before it is disposed of. This may sound strange, but it is a common practice among world leaders. The reason: An “uncleared” toilet can be tampered with in such a way that it captures the waste of its users. Theoretically, the waste can then be examined by foreign intelligence to learn about the president’s health, food habits, and the kinds of medicine he uses. This is why the so-called ‘toilet security’ has a much more important job than you may think.
Of course, no system is perfect, and sometimes nature’s call can disrupt the schedule. One such occasion allegedly occurred during a 30-minute visit of President Barack Obama to the Royal Institute of Technology library in 2013, when he met several researchers working on renewable energy solutions. Toward the end of this visit, it is said that he went to the toilet right before he left.
Shortly after the visit, a plaque was erected at the toilet in question, reading: “U.S. President Barack Obama sat here Sept 4 2013.”
While library staff can confirm that the sign was placed there by a library employee, nobody knows for sure if the president actually sat on the toilet—or that he used it at all.