politics, in short, what did Wall Street exactly do to cause all this outrage?

Disclaimer: I only recently started reading/watching the news very often and checking these sort of subreddits. With that said, I don't have a full understanding of what led to 2008's collapse, often significantly blamed on the greed of Wall Street/corporations/etc. Today's news is mostly about the aftermath, reactions, and protests about it, instead of recapping what all went down. Is there an article succinctly summing it up about what the people on Wall Street specifically did to contribute? From my understanding they recklessly "bet" on financial matters, profiteering or effectively playing dice with people's money. But that's not specific. Correct me if I'm horribly wrong but I'm basically looking for more specific things/instances than generalities like "corporate greed." Did they influence politicians to further the greed? What are some specifics? In no way am I doubting any of it, I'm just trying to better inform myself about the specifics of what went on so I can more intelligently defend some of my thoughts on politics.

Thank you.