Where are your old tyres ? - Mr X
tinyurl.com/dyxmod

Heard of this sort of thing before. Some one rents large un occupied warehouse, pays the rent on time and then vanishes. ware house owner turns up to find the place stuffed with old tyres.
Of course as the law stands, the warehouse owner is left to pay for their proper removal and disposal. This scam has also been worked on small lock ups so if thats your business, I'd keep a closer eye on them.
Where are your old tyres ? - Ian (Cape Town)
More local anecdotes...
Scrapped tyres are invariably acquired by unscrupulous types and burnt, to get the wire reinforcement out, which is sthen sold as scrap.
Obviously it takes a LOT of wire to make a decent sized bundle, so a LOT of tyres get burned.
At one stage a few years ago, the main highway past the local airport was closed as thick black tyre smoke drifiting from a nearby informal settlement made visibility virtually nil.
Where are your old tyres ? - L'escargot
Recycle your old tyres into footwear.
www.hollowtop.com/sandals.htm
Where are your old tyres ? - Cliff Pope
Give them to Rattle.
Where are your old tyres ? - FotheringtonThomas
I've tried this. As it says in the article, "not with steel belted tyres".