To act the fool. This is not a sexual reference as one might assume.

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.

British origin.
Evolving from the term of abuse bugger, meaning a sodomite or irritating person. To play 'silly buggers' is to generally act the fool, lark about, waste time or generally mess things up. As illustrated by English band The Bus Station Loonies song "Playing Silly Buggers" (1995).

1. Act performed by politicians in the day to day business of pretending to govern.
2. Employed in business sector to evoke questions of intellectual capacity, integrity and competence.
3. Smart-alec behavior in any meeting format deemed useless.

Of British origin, often heard in British, Canadian, Australian and New Zealand army units whjen referring to someone who behaves stupidly while in combat. Sometimes the expression can also be used to refer to going off on exercises.