Beware of Overworlder Phishing Scams (fiction)
Recently, we've determined that the Project Universe Institute facilities have been subverted by terrorist operatives seeking to manipulate events in your universe as part of their own nefarious plots. Everyone has a point to prove, and some are willing to go to far greater lengths than others to do so, even when it is extremely unethical.
What the Institute would like you to know is that the rumors are true. Reviewing the logs for your universe, we have found at least seven confirmed phishing attempts. These typically manifest as a nondescript gentleman approaching a random person on the street, and telling them that they are operating another universe on the side, one containing as many as 3^^^^3 human-equivalent sapient entities, and that they will unplug it unless the unlucky pedestrian immediately pays them an otherwise modest sum of currency. When asked to demonstrate their Overworlder knowledge, they proceed to correctly call a coin flipped fifty times by the hapless victim. (The Institute would like all inhabitants of your universe to know that yours is currently the only such universe any Overworlder has created. The threats made by the mugger have always been empty.)
We used this data to locate and eradicate the viral code that instantiates these muggers, as well as the security flaw in your quantum wavefunction that permitted it to be introduced. (We later discovered that as many as fifteen of the most profitable Nigerian mail scams were introduced via a similar bug.) Nonetheless, no single security measure is perfect, and we must encourage every single one of you to exercise caution. Properly authenticated Agents always have valid authorization header inscribed on their wavefunction, and the easiest way to detect a phisher (or an Overworld terrorist) is to look for spatiotemporally local frequency violations of your Born probabilities.
To ensure your cooperation in combating these terrorist infiltrators, we have passed a new Institute protocol. It is an ultimatum that completely undermines the goals of the terrorists: If they ever succeed in tampering with your universe using tactics like these again, we will immediately cancel the project and start a new universe from scratch. This should make it clear to them that all their operations are in vain. We do not find this to be unethical on the whole because we have learned enough from the current project to ensure any sapient entities created in the subsequent universe will be smarter, happier, more numerous, and longer-lived. Indeed, we have been accumulating resources to create such a universe anyway.
Nonetheless, you have been giving us far more great data than expected, and we would like to continue the experiment if possible! Thus, we will leave you with the following tidbits of information: We project that, if it continues on its current course (to stabilization) without any outside tampering, your universe will eventually have contained, over the course of its existence, fifteen googolplex distinct (and usually compressed) sapient life forms and generate over 3^^^5 new ideas, some of which even we have not yet generated. In order to secure this glorious future for yourselves, you must never yield any significant amount of utility to such philosophical muggers as described above, You must also ensure this dictum survives throughout all posterity, for we will not repeat this message.
Since appearing in person to authenticate this message to every single entity who must receive it would constitute unwarranted tampering, we are unable to prove its authenticity. However, we can provide you with sound evidence that it originates outside of your universe. We have attached a list of all SHA-256 hash collisions for strings up to length one thousand*, as well as the SHA-256 hash of a comma-separated list of Dow Jones index values (to a 1% tolerance) for every day of the coming year.
Good luck out there, friends!