Of the three smart home security companies, only Ring's two-factor requirement is active today. Nest's is due to take effect sometime in the second quarter. Still, Arlo's move is an important start. There's a mounting concern that intruders can use security cameras and other connected devices to spy on and harass homeowners. Two-step logins won't guarantee that your account stays secure, but they will raise the base level of security and prevent attackers from 'casually' hijacking some of your most important devices.