U.S. Ambassador John Tefft on the left.
Ksenia Sobchak says that standing outside the memorial, someone walked up to her and said, "Keep in mind, you're next, Ksenia."
Video from the memorial. Nemtsov's mother, Dina Eidman, is at center.
The line for Nemtsov's memorial is massive.
Outtake from Chubais eulogy:
"For 25 years, Borya had been under pressure," said Anatoly Chubais, a fellow reformist official in the 1990s under President Boris Yeltsin -- when he, Nemtsov, and Yegor Gaidar were dubbed the 'Three Heroes' -- who now heads the state nanotechnology company.
"He never betrayed anyone," Chubais said.
As Nemtsov's coffin is driven away, some in the crowd chant, "Russia will be free."