We were just ejected from the sidewalk in front of the Boston Common theater, where we were handing out leaflets about DRM to people passing by or entering to see the new Pirates movie. We were not obstructing traffic or bothering people aggressively. But after an hour and a half, we were informed by officer 284 that the entire sidewalk is privately owned. He said that we either had to move down a couple blocks, or cross the street to the park. We expressed our disbelief that a sidewalk in downtown Boston along a major road (Tremont) could be privately owned, but he was adamant. He said that most sidewalks in the Downtown Crossing area are in fact privately owned. He insisted that the nature of the protest was fine, and that we just needed to move. This was contrary to what an earlier officer had told us, but apparently the whim of the property owner changed.
So, yes, you walk through the seemingly public areas downtown only at the whim of the property owner. Free speech does not exist there. On a positive note, people were very receptive and understandably upset about the fact that technology is being used by companies like Disney to prevent copying that the law actually permits.