Craig Bidois, a former UN security advisor who runs the New Zealand-based travel security firm Fear Free, said governments take many factors into consideration before instituting a travel warning, and crime is more likely to precipitate a travel warning if foreign nationals have been actually singled out as targets.

BBC: Central America��s shift in safety

Online dating giants such as Match.com and eHarmony say it's usually best to take into consideration many factors, not just one, in finding a partner.

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It was permissible to take race into consideration as one among many factors, though racial quotas were illegal.

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