Seth D. Baum, Jacob D. Haqq-Misra, Shawn D. Domagal-Goldman
(Submitted on 22 Apr 2011 (v1), last revised 16 Aug 2011 (this version, v2))

Abstract: While humanity has not yet observed any extraterrestrial intelligence (ETI), contact with ETI remains possible. Contact could occur through a broad range of scenarios that have varying consequences for humanity. However, many discussions of this question assume that contact will follow a particular scenario that derives from the hopes and fears of the author. In this paper, we analyze a broad range of contact scenarios in terms of whether contact with ETI would benefit or harm humanity. This type of broad analysis can help us prepare for actual contact with ETI even if the details of contact do not fully resemble any specific scenario.

More @ http://arxiv.org/abs/1104.4462

Aliens may destroy humanity to protect other civilisations, say scientists

http://www.guardian.co.uk/science/2011/aug/18/aliens-destroy-humanity-protect-civilisations

It may not rank as the most compelling reason to curb greenhouse gases, but reducing our emissions might just save humanity from a pre-emptive alien attack, scientists claim.

Watching from afar, extraterrestrial beings might view changes in Earth’s atmosphere as symptomatic of a civilisation growing out of control – and take drastic action to keep us from becoming a more serious threat, the researchers explain.