For years, the tech giants have faced down their critics unabashed. But now there are signs of change. In June, Google said it would invest $1bn in housing and Facebook has also pledged $1bn. Apple upped the ante this month, saying it would devote $2.5bn to the issue.
"We know the course we are on is unsustainable," Apple boss Tim Cook said as he revealed his firm's plans. Those moves followed a flurry of smaller donations and activity from firms such as Cisco and Microsoft, which said it would invest $500m in housing in its home state of Washington.