"Many later commented on the fact that large numbers of those engaged in the most senseless acts of destruction were left well alone by cops, indeed people dressed as Black Block members were seen freely making their way across police lines and talking to cops"

This quote by John Blair recommends that the police were not doing something about it versus those engaging in senseless acts of destruction. It appears that the police were allowing individuals impersonated Black Block members to travel through their lines and even speak with them. This might be analyzed as the authorities disregarding to the damage, or even tacitly excusing it. It could also be seen as a sign of the police not wishing to intensify the circumstance by engaging with the Black Block members. Whatever the factor, it is clear that the cops were not acting versus those taking part in damage. This might be seen as an indication of the authorities not wanting to more inflame the circumstance, or it might be viewed as an indication of the cops not wishing to take duty for the damage.