2016 will be remembered as the year that Donald Trump, a reality TV star and real estate mogul with zero political experience, was elected president. But it will also be remembered as a year of heightened, vicious online harassment.

No one was safe from the vitriol. Black celebrities, Jewish journalists, white college students. The trolls latched on to the most minute of things and ran with them -- spewing racist rants and death threats with abandon.

SNL comedian Leslie Jones was inundated with racist tweets and had her personal information exposed and website hacked. Reporter Julia Ioffe, who wrote a profile on Melania Trump for GQ, was targeted with antisemitic tweets, including a cartoon of a man being shot execution-style.

Sports reporters Julie DiCaro and Sarah Spain were harassed so aggressively that they made a video of it. Men read tweets out loud like, "One of the hockey players should beat you to death like the whore you are" and "hopefully this skank is Bill Cosby's next victim." "There are a lot of "c" words here," one of the men says uncomfortably.

In 2015, game developer Brianna Wu told CNNMoney that the internet had hit rock bottom. She received more than 100 death threats that year alone, something she describes as "emotional terrorism."

But she had yet to see 2016, the year when some of her attackers were publicly validated.

Trump named Steve Bannon, former executive chairman at Breitbart, as his chief strategist. Breitbart is a right-wing outlet that has become known for its incendiary content and conspiracy theories. It's a preferred outlet for many Trump supporters and gained increased visibility throughout the election.

People like Wu have been the subject of some of its incendiary articles, which have spurred more online harassment. It has run stories like "Double Standards: Leslie Jones' Racist Twitter History," which drove more online attacks on Jones.

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"Cyber hate jumped from small groups or niche communities into the mainstream in ways that are really troubling," Anti-Defamation League CEO Jonathan Greenblatt told CNNMoney.

Greenblatt says it's the first year that an internet meme made its way into the ADL's database of hate symbols. Pepe the Frog transformed from a benign cartoon frog into a canvas for peddling anti-Semitic and racist beliefs online. Echo or triple symbols ((( ))), a means of "tagging" Jewish people online, were also added to ADL's list this year, a symbol that spread with incredible "speed and velocity," said Greenblatt.

Trump himself can be credited, at least in part, for inciting online harassers.

"When Donald Trump turns on private citizens ... he knows there's a dog whistle effect," Massachusetts Representative Katherine Clark told CNNMoney.

Trump isn't issuing threats himself, Clark noted, but "he knows he has followers who will."

People come to Trump's defense in droves -- and they do it viciously. When a former People magazine reporter went public with a story of Trump sexually assaulting her, Trump's supporters hit her with personal, public attacks.

Even something as seemingly benign as a retweet has exponential power when you're Trump. He has retweeted conspiracy theorists who call the Trump sexual assault allegations "a hoax."

"He has legitimized and encouraged violent behavior toward those who dissent," added Clark.

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In 2015, 18-year-old Lauren Batchelder was targeted by Trump in a tweet after she asked him a question at a rally.

He called her an "arrogant young woman" who "questioned me in such a nasty fashion." His followers took the bait and went after her in droves, publishing her address and flooding her inbox with threats, including rape.

"I didn't really know what his supporters were going to do, and that to me was the scariest part," Lauren Batchelder said in an interview with the Washington Post.

It's unsurprising to people like Clark, who has been using her political platform to fight online harassment.

"It's a trend that I think we all should be concerned with," Clark said, noting that she's seen threats ranging from rape to dismemberment.

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While Congress amended the Violence Against Women Act in 2006 to prohibit online threats of death or serious injury, there's been little implementation. Clark says law enforcement and tech companies need to step up to keep people safe.

Firms like Twitter (TWTR), Instagram and Reddit have rolled out new features to give users more control over what they see in their feeds, but critics say the efforts have been haphazard and too little, too late.

Clark has introduced several cybercrime bills that would create new guidelines for law enforcement and citizens.

Her most recent bill, introduced this month, addresses something known as "doxxing." It's when trolls dig up personal information like someone's home address and phone number and publish them with the intent of threatening their safety

This can also be used for "swatting," where people call in a threat to the victim's address, sending emergency responders (often a SWAT team) -- but it's all a hoax. It's a costly misuse of resources, not to mention that it can be physically and emotional harmful for victims. Clark introduced legislation to criminalize swatting in November 2015.

Her online abuse bills have been stalled in the House, but she hasn't given up. The most recent "Pizzagate" situation continues to illustrate why there's an urgent need for legislation. Weeks of online threats hurled at a D.C. pizzeria owner became a real-life horror when a gunman showed up at his shop in December.

"I unfortunately think it's inevitable that someone gets very seriously hurt," added Wu.