Aimlessness - a street photograph - (and the question of aggression)

I decided to participate in a Street Photography project ...
http://streetphotographynowproject.wordpress.com/about/

The current topic was aimlessness and the photograph below was made by asking a friend to kick an empty carton from a waste bin along the edge of the pavement ...

my choice from a little over 100 photos made

While I was engaging in this simple photographic act, a security guard came out at one point and can be seen talking through a talking device of some kind. I did not notice this at the time!

A security guard checks on my activities

The photographer Andrew Glickman who studied with Joel Meyerowitz (whose instructional video on street photography is worth seeing ... http://www.youtube.com/watch?v=5Qjym5uliDw&NR=1) remarks that "Photographing people, particularly people you don't know, is an inherently aggressive act. I had to break through my comfort zone to make some of the pictures I've made. You can't worry about whether you have permission or whether you may be inside your subject's comfort zone. Believing completely in what you are doing is critical."

Does this kind of attitude explain the appearance of the security guard who thinks that I might be up to something? The extent to which photography is aggressive (a sentiment aired by Susan Sontag in her book On Photography) surely depends on the disposition of the photographer. I do not enjoy being invasive and am of course, in this instance anyway, just photographing someone I know who is happy to be photographed.

Bruce Gilden is an example of a street photographer who is up front and aggressive though one does feel he is also often being playful!

http://www.youtube.com/watch?v=IRBARi09je8&NR=1

here he talks about the "ethics" of what he is doing ...

http://www.youtube.com/watch?v=iWEzm2disjM