What does mean by “‘we’ are responsible'”?

Along
with our freedom to live our lives as we will comes an obligation to
allow others to do the same. We don’t live in isolation. We live in a
society, a government for and by the people. We are responsible for each
other. We have the right to worship freely and safely; that right was
denied to Sikhs in Oak Creek, Wisconsin. The right to assemble
peacefully; that right was denied shoppers in Placimus
(ph), Oregon, and moviegoers in Aurora, Colorado. That most fundamental
set of rights to life, liberty and the pursuit of happiness,
fundamental rights that were denied to college students at Virginia Tech
and high school students at Columbine and elementary school students in
Newtown; and kids on street corners in Chicago on too frequent basis to
tolerate; and all the families who never imagined they’d lose a loved
one to — to a bullet, those rights are at stake. We’re responsible.

— President Barack Obama