Just before leaving an incredibly sensitive job in the single most competitive part of the financial sector for a job paying 3x at an arch-competitor of his current firm, a programmer cloned a huge collection of source code --- the majority of which was proprietary and not open source taken from the single most sensitive technical asset at his firm, an asset which his new 3x job at the competitor was to reproduce, and uploaded it to an offshore Subversion hosting service nobody had ever heard of before. Later, he is shown to have presented portions of that code to his new firm.
The only people on HN who think this is OK have that view solely because they think it's OK to do virtually anything to Goldman Sachs, because of the abuses Goldman Sachs has inflicted on the world's giant squid population.
That is a fine and intellectually coherent position to take: firms who harm giant squids do not deserve the protection of law. But people holding that position should be clearer about it, and constrain themselves to squid-based arguments.
Once a bit of copyleft code is modified and included in a binary, the legal question of whether the result is open source is not trivial and certainly open for discussion. That being said, it is certainly the intention of many people releasing the code under copyleft licenses that any modified work be open source. It is completely unfair to project the idea that all people siding with Mr. Aleynikov do so solely due to animosity towards Goldman Sachs.
It is completely circumstantial that he tried to hide the fact that he made a personal copy. It is often best to avoid having a discussion. I try to hide from my parents the fact that my wife and I... well you get the idea.
If this is true, it's a pretty big smoking gun. You really do your argument a disservice with the squid thing.