> The 4th big is twitter? I thought it was Microsoft. I don't know, maybe it was Microsoft. I haven't put much thought about what is "the big four". To me, the

> The 4th big is twitter? I thought it was Microsoft. I don't know, maybe it was Microsoft. I haven't put much thought about what is "the big four". To me, they all fall into the same bucket: big, computers, mostly US.