Handing out leaflets - is it legal and free?

Probably this is one for the locals among us, but everytime I walk up the escalators to Mid Levels always get a property leaflet shoved in my hand. Can anyone hand out leaflets and is it free to do so?

Thanks

Leaflets in Hong Kong

I'm not sure if it is legal or not, but I've never seen any leaflet-giver get asked to stop by anyone official. I tried it on a small scale a couple of years back, trying to get attention for a product I was selling. I don't think it generated any inquiries!

MrB