We've all seen them, the men in open-backed trucks who trawl the streets looking for scrap metal to collect - even if it's not unwanted.
And while it's fair to say it's only a few bad pennies who have given scrap men a poor reputation, the majority of traders are honest and upstanding.
Increases in metal theft driven by the rise in prices have had a wide ranging impact, and cost the economy between £220million and £777million a year, according to recent estimates.
It has seen disruption to energy supplies, transport and telecommunications, as well as manhole covers stolen and war memorials desecrated.
That's not to mention the number of items taken from outside people's homes - bikes, garden furniture, even motorbikes - when they are clearly not unwanted.
There are, of course, exceptions to the rule. Only this week, a Houghton scrap metal dealer was prosecuted for trading without a licence.
But what are the rules and regulations regarding disposal of scrap metal - and how could you unwittingly end up breaking the law?
Rules and Regulations
Since 2013 the industry has been more regulated than ever, in a bid to clean up its tainted image.
According to industry body the British Metals Recycling Association (BMRA), some 15,000 people are employed in the scrap metal industry in the UK.
This covers everyone from mobile collectors - usually a man in a van, and a mate or two - to large, multinational operators.
Whatever the size of the company, they are governed by the Scrap Metal Dealers Act (SMDA) 2013,.
It came into force on 1 October 2013, when new licence applications to work as a dealer were first accepted by local councils.
The newer Act repealed earlier Acts and created a revised regulatory regime for the scrap metal recycling and vehicle dismantling industries in England and Wales.
Can I get cash for my old scrap metal?
Absolutely not. It is now illegal for anyone to buy scrap metal using cash.
Instead, dealers can pay using a crossed cheque, a pre-paid card system or an electronic transfer of funds.
If you are offered cash you can report it anonymously. Report a dealer who is buying scrap metal for cash here
What checks are made on sellers?
Scrap metal dealers are required to verify the identity of all sellers, whether they're bringing them a clapped-out car, or a truck-full of old fridges and mangled bicycles.
Sellers must bring either a valid photographic ID that includes their full home address, or a formal document such as a utility bill and a valid photographic ID.
Valid forms of ID include a passport and photocard driving licence.
Acceptable formal documents include bank or building society statements, utility bills or council tax documents.
It is illegal to be paid cash for your scrap metal, including from your home address. You need to provide identification and the dealer requires a scrap metal dealer's licence.
What checks are carried out on scrap dealers?
Before anyone is allowed to work as a scrap metal dealer, they must apply for a licence from the local authority.
This applies whether they are a scrap metal merchant who collects door-to-door, or a site which disposes of collected waste metal.
The BMRA works closely with the Environment Agency, local authorities, the police and British Transport Police to ensure dealers comply with all regulatory requirements.
To check if your local scrap metal merchant has a licence, you can search the Environment Agency's Public Registers.
The local authority has the power to revoke a trader's licence if they are convicted of breaching any of the rules and regulations.
What can I do if I suspect someone is stealing metal?
The BMRA encourages the public to report scrap yards which are breaking the law by paying cash, and it also runs a metal theft alert system.