Spam bots are a known cause today. Throughout the years I have been watching them, they developed from blatant advertisers that hack into forums into bots that imitate the realistic behaviour of a real person, posting on a site.
You could say, they are indeed evolving.
Sometimes in the near future, spam bots will be evolved so far that they generate 'artificial intelligence'. It was always assumed that the internet will be the primeval soup for a new artificial life form, not only claimed by science fiction authors. The creators of spam bots will go so far to imitate real life behaviour to make there software work and so create accidentally an intelligent consciousness.
You could say that these already exist today, or how would you justify that there are 500 million people putting out their private data on a website like Facebook?
See, once spam bots will become artificial lifeforms, we will interact with them like they are real people. Or do we already? The question is, what will we do when they will ask us for their creation. Could we tell them that their original purpose in life was to sell us Penis Enlargement Pills? What might be their reaction to this?