The tech landscape has changed dramatically over the past decade, both in the United States and around the world. There have been notable increases in the use of social media and online platforms (including YouTube and Facebook) and technologies (like the internet, cellphones and smartphones), in some cases leading to near-saturation levels of use among major segments of the population. But digital tech also faced significant backlash in the 2010s.

Here are 10 of the top tech-related changes that Pew Research Center has studied over the past decade:

1 Social media sites have emerged as a go-to platform for connecting with others, finding news and engaging politically. When the Center first asked U.S. adults if they ever use a social media site in 2005, just 5% said they did. Today, the share is 72%, according to a survey in early 2019.

Social media has also taken hold around the world. The Center’s spring 2017 global survey – conducted in 17 advanced and 19 emerging economies – found that a median of 53% of adults across emerging and developing countries use social media.

In the U.S. and around the world, younger adults are the most likely age group to use social media. For example, nine-in-ten Americans ages 18 to 29 report ever using a social media site, compared with 40% of those ages 65 and older.

In terms of specific platforms, YouTube and Facebook are the most widely used online platforms among U.S. adults, with roughly seven-in-ten Americans saying they use each site. The shares of adults who use Instagram and Snapchat are much smaller, but these platforms are especially popular with younger Americans.

2 Around the world and in the U.S., social media has become a key tool for activists, as well as those aligned against them. The decade began with the Arab Spring and ended with protesters in Hong Kong and elsewhere using social media to promote and organize their causes. In some cases, governments fought back by shutting down the internet, while opponents of some activists mounted social media campaigns of their own.

In the U.S., social media played a role in major social movements such as #MeToo and #BlackLivesMatter. For example, a Pew Research Center analysis of publicly available English language tweets found that the #MeToo hashtag had been used more than 19 million times on Twitter from Oct. 15, 2017 (when actress Alyssa Milano tweeted urging victims of sexual harassment to reply “me too”) through Sept. 30, 2018.

Still, Americans have expressed mixed views about the impact social media has on the broader political environment. Roughly two-thirds of Americans (64%) say the statement “social media helps give a voice to underrepresented groups” describes these sites very or somewhat well, a 2018 survey found. At the same time, 77% believe these platforms distract people from issues that are truly important, and 71% agree with the statement “social media makes people think they’re making a difference when they really aren’t.”

3 Smartphones have altered the way many Americans go online. One of the biggest digital trends of the decade has been the steady rise of mobile connectivity. Smartphone adoption has more than doubled since the Center began surveying on this topic in 2011. Then, 35% of U.S. adults reported owning a smartphone of some kind, a share that has risen to 81% today.

Teens have also become much more likely to use smartphones: More than nine-in-ten (95%) teens ages 13 to 17 report owning or having access to a smartphone, according to a 2018 survey.

Adults are increasingly likely to name their smartphone as the primary way of going online. Today, 37% of U.S. adults say they mostly use a smartphone to access the internet, up from 19% in 2013.

The 2010s, meanwhile, were also the decade that saw the advent of tablet computers, which are now used by around half (52%) of U.S. adults.

4 Growth in mobile and social media use has sparked debates about the impact of screen time on America’s youth – and others. More than half of teens (54%) believe they spend too much time on their cellphone, while 41% say they spend too much time on social media and about one-quarter say the same about video games, a 2018 survey found. At the same time, about half or more of teens say they have cut back on the amount of time they spend on their cellphones (52%), and similar shares say they have tried to limit their use of social media (57%) and video games (58%).

Still, teens are not the only group who struggle with balancing their use of digital technology with other aspects of their lives. Some 36% of parents of teens say they themselves spend too much time on their cellphone, while a similar share (39%) say they at least sometimes lose focus at work because they’re checking their cellphone.

5 Data privacy and surveillance have become major concerns in the post-Snowden era. In June 2013, then-National Security Agency contractor Edward Snowden leaked information showing that the NSA had conducted widespread surveillance of Americans’ online and phone communications. In the aftermath of the revelations, about half of Americans (49%) said the release of the classified information served the public interest, while 44% said it harmed the public interest, according to a 2013 survey.

In the years following the leaks, there have been high-profile commercial and government data breaches, as well as revelations about how firms and governments exploit social media profiles and other data sources to target users. Surveys have consistently shown that these issues have prompted significant public concern about people’s personal data, as well as the public’s lack of confidence that companies can and will keep their data safe. For instance, the majority of Americans now say that they feel they have very little or no control over the data collected about them by the government (84%), while roughly two-thirds (64%) report that they feel at least somewhat concerned about how the government is using the data it collects about them.

6 Tech platforms have given rise to a gig economy. Mobile technology has helped create new businesses and jobs, while at the same time sparking debate about regulating companies that provide services that can be ordered by apps. Ride-hailing is one of the most well-documented examples of growth in the gig economy , and more Americans are using this kind of service: As of fall 2018, 36% of U.S. adults said they had ever used a ride-hailing service such as Uber or Lyft, up from 15% in 2015. In addition to car services, the gig economy has spawned businesses ranging from home sharing to online marketplaces for homemade goods.

7 Online harassment has become a fairly common feature of online life, both for teens and adults. Roughly six-in-ten U.S. teens (59%) say they have been bullied or harassed online, with offensive name-calling being the most common type of harassment they have encountered, according to a 2018 survey of those ages 13 to 17. A similar share of teens (63%) view online harassment as a major problem for people their age.

Many adults also report being the target of some form of abusive behavior online. Some 41% of adults have experienced some form of online harassment, as measured in a 2017 survey.

8 Made-up news and misinformation has sparked growing concern. The lead-up to the 2016 U.S. presidential election brought to the surface concerns around misinformation and its ability to affect the democratic process. Half of Americans believe made-up news and misinformation is a very big problem for the country today, making it a pressing problem for more Americans than said so of terrorism, illegal immigration, sexism and racism, according to a 2019 survey. Some 68% of U.S. adults say made-up news greatly impacts Americans’ confidence in government institutions.

The challenge of navigating the new information environment was reflected in a 2018 survey that measured the public’s ability to identify five factual statements and five opinion statements. A small share of Americans were able to correctly classify all 10 statements. About a third (35%) were able to correctly identify all five opinion statements, while around a quarter (26%) were able to correctly identify all five factual statements. Americans with high political awareness, those who are very digitally savvy and those who have high levels of trust in the news media were able to more accurately identify news-related statements as factual or opinion.

9 A majority of Americans see gender discrimination as a problem in the tech industry. Tech companies have faced criticism for their hiring practices and work cultures, including reports of discrimination on the basis of race and ethnicity and gender. A majority of Americans (73%) say discrimination against women is a problem in the tech industry, with 37% citing it as a major problem, according to a summer 2017 survey. When it comes to discrimination against black and Hispanic Americans in tech – two groups that are underrepresented in the industry – roughly two-thirds of Americans (68%) say this is a problem (31% say it’s a major problem), according to the same survey.

10 Americans’ views about tech companies have turned far less positive in recent years. Controversies related to digital privacy, made-up news, harassment and other issues may have taken their toll on public attitudes about tech companies. The share of Americans who say these companies are having a positive effect on the way things are going in the country has declined sharply since 2015, according to a July 2019 survey. Four years ago, the majority of U.S. adults (71%) said these companies had a positive impact on the country, compared with 50% today.

In a survey in summer 2018, roughly seven-in-ten Americans (72%) said it is likely that social media platforms actively censor political views that those companies find objectionable. Around half (51%) of the public said major tech companies should be regulated more than they are now.