http://www.businessinsider.com/the-biggest-biotech-discovery-of-the-century-is-about-to-change-medicine-forever-2015-2 a rather long but interesting article about the DNA editing tool CRISPR.  This tool was not created, rather it was found.  Microbes (or whatever they are called) have been using this to defend against invasion for a long time.  The way the article makes it out to be that there exists a war at the micro scale being waged constantly.  The combatants aren’t dumb either.  They have a memory, they have tools, they communicate, they learn!  It is truly amazing.  What kind of mechanisms do they have to cooperate?  http://www.ncbi.nlm.nih.gov/pubmed/22999189 discusses this and this article talks about how cancer cells cooperate and even have free riders.  In order combat the cancer they change the code of the dna to make it so that there are more free riders so the tumor dies.  Cellular organization is very elegant.

This is interesting.  In the future this could be a way to hack a MAS that may be built on similar principles.  The fact is that we try to avoid freeriders but if the system is flooded with them the system will decay.