(1) When some people see people with visible disabilities, they may have an adverse reaction that has more to do with their fears about their own body integrity (i.e. "Could this happen to me?") or fear of their own mortality. It is similar to when people see a car wreck on the side of the road... most everyone slows down to look, right? Why? Curiosity and fear. So you see, it has more to do with them, than the person with the disability. I realize it is still intrusive and sometimes downright rude of them, but it helped me have some compassion for these rubber necking "lookieloos" once I understood that it has less to do with me, and more to do with "them." I now focus on the 90% of the people out there who have been really sweet and supportive to me.

 (2) Another possibility is this man that stared at your son had a form of autism. I volunteer for/participate in different disability events and have met 100's of people with autism by now. Depending on the severity of their case, they often do not have impulse controls. I have had autistic people (usually children) try to lift up my dress to see where my leg went...not just once... they keep coming and trying to find it!  Their caregivers are usually mortified, but I am at the point where I find it humorous.

 (3) Yet another possibility is that this man that was staring at your son was an "amputee devotee" or "amputee admirer". If you don't know what these terms mean yet, then look it up on the site here under "Groups" or Google it and you will get quite an education on this topic! Check it out: 

en.wikipedia.org/wiki/Attraction_to_disa...

en.wikipedia.org/wiki/Acrotomophilia

I am sure there are other reasons people stare... but these are just some of the ones I have experienced. 

Any disabled actors, writers, and/or producers here at >4 might find this meeting interesting. It’s sponsored by the Writer's, Producer's and SAG/AFTRA Guilds and will be held at UCLA’s (University of Calif, Los Angeles) School of Film, Theater and Television @ Melnitz Hall on October 24th 9 a.m. - 5 p.m.

www.iampwd.org/you-are-invited-the-holly...

Amputees can play more than war victim extras or Cherry Darlings at convention shows! (-:  We are just people leading every day lives and should be portrayed as such on film, stage & television. 

Although the deadlines for auditions are up, you might want to try (call) anyway, or just sign up and come out to learn what it’s about. 

Some of the speakers are: PETER FARRELLY (THERE'S SOMETHING ABOUT MARY)
VINCE GILLIGAN*, RJ MITTE (BREAKING BAD)
DARYL "CHILL" MITCHELL, JANIS HIRSCH (BROTHERS)
DAVID MILCH, GERI JEWELL (DEADWOOD), ROBERT DAVID HALL (CSI), DANNY WOODBURN (SEINFELD); LINDA BOVE (SESAME STREET)WITH A SPECIAL VIDEO APPEARANCE BY RICKY GERVAIS (THE OFFICE)

And here is another interesting article on the topic... 

www.disabilityrightsca.org/news/Back_Sta...