I love crows. I feed a pair of crows cashews every morning in my backyard. They've discovered sometime this past week that they like to dunk the cashews in the birdbath before eating them. They're a joy to watch.
Anti-hobo spikes are usually larger, made using concrete, and found on public benches, shop entrances, and other areas where the homeless might want to rest. Anti-bird spikes are usually made from plastic and mostly placed on fences, balconies, terraces, window sill, and rooftops.
Imho, both are shitty and display a severe lack of compassion.