From the article:

"They could also use this information to see whether I’m using Google Video Chat. Whether this is the purpose or not I don’t know. Regardless, they’re collecting this information from millions of unknowing users. Bad form Facebook. Bad form."

I don't think that's making big assumptions. That's just stating a fact: you don't do something invasive when it's not required or expected by the people trusting you to run software on their computer. End of story.

I think I quite clearly state that I have no idea (nor intend to presume) whether this is how they're using the information. I'm merely stating it's a possibility.