Police have launched a series of early-morning raids as part of a crackdown on the sale of stolen metal.
Seven people were arrested by officers who visited eight homes and two commercial properties in the Thanet area of Kent.
Five were held on suspicion of conspiracy to handle stolen goods and two detained on suspicion of supplying Class A drugs, Kent Police said.
The raids were launched as the Government announced that scrap metal dealers found to be linked to the theft of railway signalling cable or other stolen metal are to be barred from the industry.
Seven scrapyards were visited in Kent as part of the day of action, and staff were told about their responsibilities under the Scrap Metal Dealers Act.
Senior police chiefs said metal theft blights the lives of thousands of people, including householders and businesses who are left without power.
Kent Police deputy chief constable Alan Pughsley said: "The theft of metal is bringing misery literally to thousands of people.
"Householders are being left without power and light and businesses are unable to function when underground telephone cable is being torn out of the ground.
"The rail network has been disrupted and we have seen that thieves will even stoop as low as to rip the plaques off memorials dedicated to those who have died fighting in wars.
"At Kent Police we are determined to do all within our power to target the venues helping these thieves to function.
"Today's warrants are the result of months of work by officers who have been investigating the network involved in the metal theft trade, which we also believe is linked to the supply of controlled drugs.
"This work will not end with today's action but continue with the support of other partner agencies.
"It is pleasing to note that during our investigation we did visit yards who are acting within the law and correctly reporting to police when they are suspicious about sellers and the origin of the metal."
Chatham and Aylesford Tory MP Tracey Crouch, who attended the operation, said: "It is important that we as law makers understand what those who are enforcing the law are dealing with."