When a Wall Street program loses money for the owners, they eat it.
Not saying this is common, Knight provides a good example in the other direction and I honestly don't care enough about the markets to know of anything that didn't make national news, just that it seems it depends on the situation.
If I fuck up and code a program that goes out and buys or trades and buys illegal shit, then it's my fault for being stupid.
Legally of course this depends on the jurisdiction, IANAL. Morally I believe this is very grey area and depends primarily on intent. Obviously it's sort of hard to judge intent in most cases, though in this case unleashing it specifically on a "Dark Web" type site does imply at least some knowledge that it'll happen these days.
Then again I have to imagine part of the point of this exhibit was to counter that assumption, that all these sites are good for are illegal things.
By displaying them in such a conspicuous location also changes things compared to if one had tried to use "the computer did it" as an excuse when caught with the same things in their home.
Basically it's probably legally wrong, but I'd have a hard time being convinced that they should actually be punished for it.
Or let's put it this way, I code a program that looks for and downloads kiddie porn. Cops nab me and I just say, "Oopsie. The robot did it, not me!" So, I should get off...I mean let go?
Again depends on the context and the intent. If you wrote a bot that went out looking for anything it thinks is porn to display automatically in an art installation and it happened to come across kiddie porn, it'd certainly be illegal in a lot of jurisdictions. That said, due to the context of displaying the results of a search automatically as art I'd still be unconvinced that punishment is appropriate. The same excuse deployed by someone caught with a collection of images on their own machine should get laughed out of court and them right in to jail.