Rant: Playing Music on a Mobile Speaker Phone

I've been meaning to say something for a while but today on the bus into work was the last straw.

What idiotic engineer or marketeer decided that it would be cool to allow people play music stored on a mobile on it's speaker? The only time that is going to happen is when the person is in a crowded bus/train/building where is going to piss people off.

Now, to those people who do this. STOP. I don't care what music you like but I don't want to have to listen to it. I have my own favourite music and I don't want to have to listen to yours because you are too selfish to not use headphones. You are intruding on my personal space.

Strangely enough it always seems to be teenagers who insist on playing music on the speaker. Some people would say I could simply ask them to turn it down. Yes I could, BUT, they should never have turned it on in the first place. Why can't people think of those around them?