9 Craziest Internet Challenges

1Underboob Pen Challenge

Young women are demonstrating their femininity — by exposing their boobs for everyone to see. They are posting photos of an impressive range of objects nestled under their breasts on social media. The strange idea behind this trend is to illustrate what "real" women look like – and you need impressive cleavage to hold the object in place.

Those who are most "talented" can grasp pens, pencils, makeup brushes, bottles of lotion and even flowers with their breasts. The revealing snaps are usually accompanied by the caption, "Pass the challenge to prove you're a true woman."

2Duct Tape Challenge

A teenager was left badly hurt after taking part in a challenge that made headlines around the world. During the "duct tape challenge," participants are tied with the adhesive up for three minutes, and then have an additional three minutes to escape. The video posted is then posted to social media, where it is often widely shared under #ducttapechallenge.

But things don't always go so great. Fourteen-year-old Skylar Fish suffered severe head injuries, a brain aneurysm and damage to his eye socket, prompting serious questions as to the potential risks associated with the "challenge."

3Extreme Phone Pinching

Inspired by a video released by the band Twenty One Pilots, social media users are turning “extreme phone pinching” into the latest viral challenge. The anxiety-inducing trend involves precariously holding your phone with just your thumb and forefinger over somewhere you really wouldn't want it to fall.

A few tamer examples of the craze include dangling your phone over a balcony or in the gap of a sewer drain, although some go more daring lengths to show how risky they're willing to be with their precious gadgets.

I don't know about you guys, but my two-year-old threw my smartphone down the toilet, and that was no fun at all.

4Condom Challenge

The "condom challenge" is filling our newsfeed with shaky homemade videos of people in their swimming gear. The original video, featuring two men from Japan, has attracted nearly 276,000 views and 20,000 shares. Copycats began in earnest after word of the craze spread.

The challenge involves filling a condom with water and engaging the services of an assistant to hold it above the participant's head. It is then gently dropped onto the challenger's head and should wrap itself around the person's face and neck but remain intact, with no water being released. The condom often has to be broken to separate it from the wearer, leaving the challenger drenched.

At least there are a lot of kids using condoms — that's good news to me.

5Belly Button Challenge

In 2015, a trend known as the “belly button challenge” took off on social media. It began in China but is now worldwide, and involves mostly young people posting self-portraits while trying to reach an arm behind their back and around to touch their belly button.

Don't despair if you come nowhere reaching your waist. It appears that someone's ability to achieve the belly button challenge is not down to one's tiny waist, but rather a range of factors including flexibility and arm length.

6Fire Challenge

In 2014, a Kentucky boy was self-immolation victim of a dangerous online phenomenon called the "fire challenge." The 15-year-old later admitted he wasn't thinking of the consequences.

And he wasn't the only one — there are hundreds of videos online of people performing these stunts to various degrees of injury. It seems the point of the challenge is to spray a small amount of flammable liquid, like alcohol or perfume, on an area of the body and light it on fire. Many of the participants appear to be teenagers or younger and accidents happen if too much liquid is spread or they are unable to extinguish the flame quickly enough.

7Bikini Bridge

In 2014, a group of 4chan users circulated a series of images and tweets promoting the bikini bridge — the gap created between a woman's bikini bottoms and concave stomach when she's lying down in a two-piece.

The images, bearing sayings like "I love it when ... guys notice my bikini bridge" and "if your girlfriend doesn't have a bikini bridge why are you with her" are in the style of "thinspiration" posts that circulate on social media and pro-eating disorder websites.

The hoax resulted in thousands of tweets, as well as community posts generated by the pranksters on Buzzfeed and CNN (both of which have since been removed). It was quickly attributed to 4chan by reporters at The Daily Dot.

What started as an Internet prank can potentially do lasting damage by giving people with eating disorders a dangerous new goal to obsess over, health experts say. Even if it was dreamed up by a bunch of anonymous Internet users, the bikini bridge is "a thinspiration members' dream come true," said Lynn Grefe, president and CEO of the National Eating Disorders Association. Spreading the images is as easy as "just passing it along" via a blog or social network post, she said.

8Collarbone Challenge

On June 2015, a new social media challenge emerged in China in which web users were uploading selfies to show how many coins they could hold with their collarbones. The trending topic quickly amassed more than 34 million hits on Weibo, China's equivalent of Twitter.

The more coins you hold, the better your figure is. (The coins must be kept standing up as much as possible.)

Most participants in the challenge are women— some hold around 20 coins on a single collarbone.

There is yet to be any scientific theory to support the challenge.

9Human Flag Challenge

These are the amazing pictures that could spark the latest viral sensation. A former pro rugby player has brought the "human flag" craze to the UK. The images of Dave Jackson, 32, performing the difficult move, which is part of the calisthenics regime currently sweeping the USA, have gone viral. It involves using incredible body strength to suspend yourself sideways in mid-air to make a human flag — using a static object as the pole.

Fitness fanatics have posted pictures of themselves pulling the move off on social media and the "human flag" is being heralded as the next big web craze.