Hi Carmen,
There is a difference between the groups. "Open Source" is a tool or methadology, not a moral stance or ideology like "Free Software" is.
That's a popular stance, but I don't believe it's justified. In either case, if you hear someone talking about Open Source, you can not, from the term alone, determine whether that person ascribes to it a moral stance or not. You need to listen to what they're actually saying.
If they're talking about Open Source as a development paradigm alone, it might sometimes be prudent to remind them about our ethics. The same holds if someone talks about Free Software as a development paradigm alone.