False bravery that comes from hiding behind a computer screen. Includes (but is not limited to) saying things that you would never typically say in a face-to-face conversation, making empty threats to people you don't like, and/or making up lies just to get a rise out of people (also known as trolling). These individuals are usually quiet and backward in public, but talk shit about everyone they can while they are on facebook or another social networking site. When confronted in person, they back down almost instantly.

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.