How TikTok overtook Facebook and Instagram to become the most downloaded app on planet

• TikTok has been downloaded over 1 billion times globally, surpassing both Facebook and Instagram in app installs. 
• Three-year-old TikTok is owned by China's ByteDance, a start-up with a bigger valuation than Uber and funded by high-profile investors like SoftBank. 
• The first major social media contender since Snapchat, TikTok only recently arrived in the U.S. before landing in hot water regarding data-privacy concerns and predatory practices. 

If you haven't heard of social media app TikTok, just wait. The short-form video app designed for sharing viral memes is already wildly popular among teenagers, even landing late-night TV host Jimmy Fallon as a fan.

"What Tiktok does really effectively is reduce the distance and friction between people, other people and information. You download the app and you're instantly engaged," CNET producer Dan Patterson told CBSN. 

It's also the first major contender since Snapchat to possibly disrupt a market dominated by social media behemoth Facebook. The mere three-year-old startup even comes with a history of data-privacy controversies. 

Created by China start-up ByteDance in 2016, TikTok has already been downloaded over 1 billion times globally, surpassing both Facebook and Instagram in app installs last year, according to analytics site Sensor Tower.

TikTok was downloaded 663 million times around the world last year. For comparison, Facebook was downloaded 711 million times last year, and Instagram claimed 444 million downloads. And that number keeps ticking: TikTok clocked in 188 million more installs in this year's first quarter, winning it the top spot again among social networking apps. 

TikTok's figures are particularly impressive, not just because TikTok is a young company, but because they exclude installs from third-party Android stores in China, meaning the actual download count is much higher. TikTok, called Douyin in China, is a phenomenon in a country where both Facebook and Instagram are banned.

It's also more than just a plucky tech start-up. ByteDance, which owns TikTok, is the single largest start-up in the world, surpassing Uber in valuation with $78 billion. It has funding from some of the world's highest-profile investors, including Japanese conglomerate SoftBank (also an investor in Uber).

However, TikTok has already come under fire from government regulators and parents for data-privacy concerns and what some critics call predatory practices on the app regarding children.

History of data-privacy and predatory concerns

TikTok ran afoul of U.S. regulators in February when, after merging with Chinese-owned app Musical.ly in August, it settled a case with the U.S. Federal Trade Commission for $5.7 million, the largest civil penalty the agency has collected for a children's data-privacy case.

The FTC complaint said Musical.ly did not seek parental consent before collecting names, email addresses and other personal information and noted that "there have been public reports of adults trying to contact children via the Musical.ly app."

In response, TikTok said it would split users into "age-appropriate TikTok environments," but critics say there's no way to ensure users are telling the truth. 

In England, the social media company came under fire in February from British charity group National Society for the Prevention of Cruelty to Children when it said it surveyed 40,000 schoolchildren and discovered that one-quarter of them had livestreamed with a stranger. One in 20 schoolchildren said they were asked to take their clothes off, according to the NSPCC.

TikTok is not the first social media app to come under fire for data-privacy controversies regarding children, but while social media giants like Facebook are shifting towards privacy and insular communities, TikTok is a platform set up for viral exchanges. 

That means that information can pass hands a little too quickly -- one reason why India, which counts for 25 percent of the Tiktok app's downloads, temporarily banned the app last month over fears that pornographic content were being made available. An Indian court lifted the ban on the condition the platform not be used to host obscene videos. 

— The Associated Press contributed to this report.