I don't know any genius American crows but this stray dog behind the Saket malls (the area known as "backside") furiously and angrily chases black Thars. Second chase I saw in 5 min. Missed catching that chase on video but here he's just returning from a chase. Afterward I told him, dude, I'm with you. He wagged.
Crows (especially American crows) are highly intelligent and have remarkable abilities to recognize individual human faces, remember negative experiences with specific people for years (up to 17 in some studies), and socially transmit that information to their offspring and other crows, even those who never directly experienced the original incident.
Researchers wore distinct masks while trapping and banding a small number of crows (a stressful but non-harmful experience for the birds). The crows quickly learned to associate that specific "dangerous" face with threat and responded by scolding, mobbing, and dive-bombing anyone wearing it.
Offspring and other crows picked this up through observation: young birds (fledglings born later) would join in or react independently after seeing their parents' alarm calls and behavior. This "knowledge" spread through the local crow population via social learning, turning a personal grudge into a community warning.
[Cornell, H. N., Marzluff, J. M., & Pecoraro, S. (2012).
Social learning spreads knowledge about dangerous humans among American crows.
Proceedings of the Royal Society B: Biological Sciences, 279(1728), 499–508.
DOI: 10.1098/rspb.2011.0957]