A little late, but a story to share:
During my evening commute on Tuesday and my morning commute on Wednesday, I boarded subway cars with sleeping homeless persons. In the former situation, the sleeper had commanded an entire bench. Though people were annoyed that space was compromised during the evening rush hour, no one harassed the man. We just all packed in a little tighter instead. In the latter, the man slept in a seated position, though he still occupied at least a quarter of a bench. (I'd approximate that to be the space occupied by three people weighing about 150 lbs each.) The homeless are invisible to members of the majority in most cases. In this instance, invisibility gave them a moment's respite from the cold. The presence of these two sleeping individuals also posed a challenged to their fellow riders: these individuals were most decidedly there, but this could not be acknowledged by other riders because it would render them visible. If they actually existed, if they were rendered real by recognition, perhaps require action. Invisibility permitted them to slumber on. They were both securely in position when I exited at my destinations.
(FYI: I've talked about the efforts of two homeless individuals to attain visibility previously in this post.)