I got this idea watching trailer for FaceFactory Cinematic mod where whole trailer Dr. Breen from Half Life 2 is speaking and this is what he is saying:
Dr. Wallace Breen: It has come to my attention that some have lately called me a collaborator, as if such a term were shameful. I ask you, what greater endeavor exists than that of collaboration? In our current unparalleled enterprise, refusal to collaborate is simply a refusal to grow - an insistence on suicide, if you will. Did the lungfish refuse to breathe air? It did not. It crept forth boldly while its brethren remained in the blackest ocean abyss, with lidless eyes forever staring at the dark, ignorant and doomed despite their eternal vigilance. Would we model ourselves on the trilobite? Are all the accomplishments of humanity fated to be nothing more than a layer of broken plastic shards thinly strewn across a fossil bed, sandwiched between the Burgess shale and an eon's worth of mud? In order to be true to our nature, and our destiny, we must aspire to greater things. We have outgrown our cradle. It is futile to cry for mother's milk, when our true sustenance awaits us among the stars. And only the universal union that small minds call 'The Combine' can carry us there. Therefore I say, yes, I am a collaborator. We must all collaborate, willingly, eagerly, if we expect to reap the benefits of unification. And reap we shall.