The green avatars represent the green-screen, a key tool in visual effects moviemaking.
Changing your avatar to a green-screen represents solidarity with the computer graphics industry which is currently being plagued by bankruptcy and layoffs (like what happened to me last week ORZ…): Digital Domain, Sony Entertainment, DreamWorks Animation, Pixomondo, Zynga, and more.
The “greenscreen movement” is largely prompted by bankruptcy of Rhythm and Hues, the company responsible for two Oscar-nominated movies this year: Snow White and the Huntsman and Life of Pi. Just weeks before the ceremonies, much of their staff (the people that made those movie!) got laid off - many of those workers picketed outside the Academy on Oscar’s night. Insult was added to injury when Life of Pi won an Oscar for ‘Best Visual Effects’ and the winner’s acceptance speech was cut short as soon as he mentioned the financial issues at R&H (it may not have been intentional, but it still read terribly!).
VFX is highly competitive. When a studio wants to make a movie, VFX houses name a price they can do the work for. Obviously, studios want lower prices and faster work, so VFX houses frequently under-bid each other and ask for unreasonable workdays. Studios thus get more demanding and drive prices into unsustainable territories. In addition, some areas provide subsidies for local VFX work - up to 30%! - meaning studios only have to pay for 70% of the movie. Taxpayers cover the rest. So globally, it’s an uneven playing field. California doesn’t give subsidies, so established Hollywood houses are losing bids that were already too low to begin with. This Reddit post does an amazing job explaining the situation.
While layoffs are familiar in project-based industry, this is a LOT in just a few months, and it brings an unhealthy business model to public light. I encourage you - if you want to work in this field or simply enjoy VFX movies - to research and appreciate the work that goes into them - and maybe we can collectively hope for change.
To get more up-to-date information, I suggest VFX Soldier: http://vfxsoldier.wordpress.com/.