How US home loan agencies became rental powerhouses

Fannie Mae and Freddie Mac are two US agencies that were set up to make mortgages more affordable to Americans. But the system was rocked during the 2008 housing slump and the government bailed them out. And now, critics say the home loan agencies are using taxpayer support to be a force in the commercial property market. The FT's Alistair Gray and John Authers discuss.