What you would need is a wildcat strike that threatened delivery of a product by a large producer and was supported by peers throughout the industry. It would need to be a watershed event. And before anyone says this isn't possible remember that modern unions emerged on the strength of workers who were under threat of actual violence, including death. I'm frankly shocked to see folk in this thread saying they're no longer necessary and can only assume people saying so either don't have families to support or work under more favourable conditions than some of these workers. Just because the economy is bad doesn't mean people don't deserve a voice in their workplace.
I for one am very thankful to live in a country where employment laws mean that my job is secure in the event my company changes hands, where I cannot be compelled to work more than a 48-hour week and where, if I provide 24/7 standby cover - and I do - I'm entitled to eight hours uninterrupted sleep before returning to work the next day. On top of that by law I get a minimum of 20 days paid leave per year - not including public holidays. Aside from health care that justified emigration from the USA right there. I cannot see why anyone would accept any less and I certainly wouldn't expect anyone else to just because they made games for a living. Getting the next Call of Duty out on time isn't going to replace time with your kids for heavens sake!
