Yes, this is how they deal with it. Block of sections of the sidewalk in a manner that doesn't even qualify as half-assed.
Believe it or not, this is actually one of the better jobs in terms of pedestrian convenience. Sometimes building maintenance people will just run that red tape directly out from the building to the street, so that the sidewalk is just completely blocked off.
Sometimes maintenance guys get around to going to the roofs of all the buildings and manually knocking all the icicles off when it's safe to do so.
Other times...well they don't and they just fall off on their own...hope you're on the other side of the street when that happens!