I think you can be aware or possibly even "wary" if you see that, but I think it is a little absurd to let that become actual worry or suspicion.
Just be aware of your surroundings. Clock the person in a hoodie, make a mental note of it, and continue on your way. I feel like this is "how to live in a modern city 101." If you get this thrown by seeing someone in a hoodie, then maybe you're too anxious to be around that many people