When a previous experience in the restroom with low quality toilet paper results in dinglberries so large that one cannot proceed to take a shit; this then will require immediate removal of the berries so you will be forced to take a shower in a non-familiar location without the proper resources to get the job done, so only one option remains.... your hand

The safeguarding of Earth and other worlds from biological cross-contamination (i.e. billionaires with too much time on their hands).

Also known as “planetary protection.” Planetary protection / quarantine “reflects both the unknown nature of the space environment and the desire of the scientific community to preserve the pristine nature of celestial bodies until they can be studied in detail.”

There are two types of interplanetary contamination. Forward contamination is the transfer of viable organisms from Earth to another celestial body. Back contamination is the transfer of extraterrestrial organisms, if such exist, back to the Earth's biosphere.