Now Playing: Virginia Tech student arrested for allegedly an assault rifle

Now Playing: The founder of Smart Dating Academy shares her top dating tips

Now Playing: Parent company of Tinder, Match sue Bumble

Now Playing: Facebook Lite launches in America

Now Playing: Theranos CEO accused of defrauding investors

Now Playing: Walmart plans on expanding grocery delivery to 100 metropolitan areas

Now Playing: Apple expands into journalism

Now Playing: SpaceX CEO sounds off on travel to Mars

Now Playing: Elon Musk talks of a future space flight to Mars

Now Playing: The son of an army veteran builds his father a new hand

Now Playing: Does Samsung Galaxy S9's software match its impressive design?

Now Playing: FBI paid Best Buy's Geek Squad members to act as informants

Now Playing: US concerned with Chinese smartphone maker Huawei

Now Playing: Facebook survey asks British users if adults can ask minors for explicit photos

Now Playing: Cheaper MacBook may be on the horizon

Now Playing: Equifax massive data breach impacts additional 2.4M people

Now Playing: Spotify announces plan to go public

Now Playing: Testing the protection of bulletproof backpacks

Now Playing: Bitcoin's mysterious beginning and how its use has changed

Now Playing: What is bitcoin, the world's most popular cryptocurrency