Six men were jailed for 17 million in fraud charges for selling solar panels to the elderly, retirees and vulnerable groups.
According to the Office of Serious Fraud, 1,500 victims were "manipulated" to buy panels and promised to recover funds from their investments.
But the jury heard that the group spent money on sports cars and holidays.
Ludovich Black, David Diaz, Robert Ross, Kenneth Reed, Stephen Wilson and Neil Hasty were jailed after being tried at Liverpool Criminal Court.
They run a company called Solar Savings Limited, which is based in Manchester and is no longer open.
The court heard that the victims had been promised to invest in the installation of panels and that they would recover their money within five years, but because they had never invested, the money had not been returned.
Office of Serious Fraud（SFO)
Saying that the victim was "manipulated" by "deceptive sales skills, outright lies and false guarantees of compensation" ultimately resulted in a loss of between 10,000 and 20,000 pounds per victim.
Two brothers, David Diaz and Ludovich Blake, from Glasgow, were arrested 11 months after their escape in a routine police traffic check in Cheshire and tried in April.
QC, which sued Alastair Webster, said the fraudsters used a "hypocritical and cynical pamphlet" with a series of lies.
He said they were "totally indifferent to the impact on customers".
Lisa Osofsky, director of the San Francisco Securities and Exchange Commission (SFO), said: "These people have established predatory schemes to steal thousands of people from their plight. " -
While pretending to provide vulnerable groups with opportunities to improve their financial security, they won savings.