This really annoys me too, and I think you are right to just ignore them they want to cause a scene, anything to bring more attention to them.
But the sickest I have ever felt was when i witnessed a religous group protesting at a military servicemans funeral because they didnt agree with the military's stance on "dont ask dont tell". I couldnt believe what I was witnessing! I felt so bad for the family of the serviceman, there was nothing they could do. The protesters werent breaking the law. It wasnt like the they had any control over the military's stance on the issue. That group was doing it solely for shock affect to make the news and further their agenda, they could care less who they hurt along the way. This was this families last chance to say goodbye to their loved one wheo served to protect the rights of these morons and they couldnt even do it in peace. I for one am grateful to all military service members who have served our country!
Sorry I dont want to change the subject but to me it is very similar, they want attention and will go to great lengths for it.