system
Given the following post, respond as if you're commenting on Reddit:
human
[MCU] How did Tony find out Peter Parker's secret identity?
gpt
Geographic Profiling. Peter’s heroics are clustered nearby his place of residence which narrows down the list of potential suspects considerably. Even more so considering there are two clusters, his house and Midtown High. 

Then you exclude the ones that don’t match the physical dimensions of Spider-Man and you are left with a small number of potential suspects. 

Once you have that small list you check their social media to see if you can find a digital alibi for the person. Because of the number of Spider-Man incidents it’s fairly easy to show that each false suspect has been online during at least one of them and thus can’t be Spider-Man.