In my opinion I think the focus of this thread went to deep into the Bondage/Submission stuff. Not to mention any poster who is in comitted relationship can't really use their current sexual partner as example since they are obviously not 'owning' in the same way that a few one night stands would be.
With that said, I think this is just a matter of symantics. Males have dominated females (not LITERALLY) in all of the last few centuries. If you want to take issue with the term 'owning' think about our terminology for what we say when we just had sex with a girl. "hit it", "tore it up", "beat it" or "beat that up", "tapped it". OR if a woman gets pregnant she gets "knocked up"? Our simple language denotes violence and dominance. This is a social issue that would involve how women change their last names to the males, how males name their cars and other objects by female names in a sense of ownership.
I apologize if I attempted to completely over answer the question but it is something else to think about rather than just saying that males are insecure. Its a host of societal factors. (One of which does include how it makes us feel more manly and its a good way to showoff to the friends)