Many filtering companies rely on analysing the text on webpages for keywords or trigger phrases in close proximity to each other.

BBC: Net filters fail the children

Toxic particles in cigarette smoke can remain on nearby surfaces, as well as the hair and clothing of the smoker, long after the cigarette has been put out, and small children are susceptible because they are likely to breathe in close proximity, or even lick and suck them.

BBC: Warning over 'third-hand smoke'

Another is interference: too many femtocells in close proximity could interfere with each other, or with existing mobile networks.

ECONOMIST: Mobile telecoms

Using your living room or bedroom for your office might tempt you into being unproductive with a TV and a bed in such close proximity.

FORBES: How To Run A Home Office On A Budget

This was, I guess, confirmed by the fact that she states that during the visits everyone was in such close proximity to one another that one could have easily heard if the case or matters were being discussed.

CNN: Juror says key witnesses lacked credibility