I think it can be loosely explained that Toomes was extremely careful not to draw attention to themselves. He usually goes on heists at night time. Maybe the authorities know that someone is stealing these alien techs but can't really pinpoint who it is or how they did it. Yeah, the security was terrible. Seemed like India. Not a fan of it because it goes against Spidey's nature but I wouldn't mind seeing him use Instant Kill Mode against Thanos and the the Black Order.