Social media can be a fantastic tool for companies to engage with consumers and create a friendly persona. But it can also be incredibly dangerous to your brand if used carelessly. Here are the 10 worst brand fails on social media from 2014. 

1. Twitter CFO gaffe

In November, Twitter CFO Anthony Noto slipped up and tweeted a message that was probably meant to be a private direct message. The tweet, which was quickly deleted, read: "I still think we should buy them. He is on your schedule for Dec 15 or 16--we will need to sell him. i have a plan." The message is thought to have been referring to Twitter's plans to acquire the selfie app Shots, which is backed by Justin Bieber.

2. DiGiorno's inappropriate use of #WhyIStayed

Following Janay Palmer Rice's decision to stay with NFL player Ray Rice after a domestic violence incident, the hashtag #WhyIStayed was trending on Twitter. DiGiorno Pizza tried to join the conversation, tweeting "#WhyIStayed You had pizza." Within minutes the inappropriate tweet was deleted and the company apologized, claiming it didn't know what the hashtag was about before tweeting.

3. US Airways' NSFW tweet

When responding to a customer on Twitter, US Airways included an incredibly inappropriate picture. It was deleted about an hour later, and the airline apologized, claiming that someone had been trying to flag the image and accidentally copied and pasted it in the customer service tweet.

4. Union Street Guest House's scare tactics

The New York City hotel had a policy of fining wedding guests $500 for negative social media posts and online reviews--that is, until the public found out, at which point the hotel claimed it was all a joke.

5. MasterCard's hashtag hijack

A PR firm representing MasterCard tried to require journalists to mention the credit card company on social media to get press credentials for the Brit Awards. The journalists were instructed to use the hashtag #PricelessSurprises. They did so, but not exactly how MasterCard had hoped.

6. Global Village Duluth's MLK Day fail

There's a nearly endless list of brands that have made ill-conceived attempts to take advantage of holidays and commemorations, so we'll just include this one as an example. This Minnesota store decided that the perfect way to commemorate Martin Luther King Day on its Facebook page was to offer "25 percent off everything black."

7. American Apparel's Challenger disaster disaster

To celebrate July 4, American Apparel used its tumblr page to post a picture of the space shuttle Challenger exploding. After receiving lots of negative feedback, the company apologized, saying that the social media manager was born after the Challenger disaster and didn't realize what the picture was.

8. Smucker's tries to monitor comments

Smucker's got a lot of flak recently for its stance against labelling genetically modified organisms (GMOs), and a lot of people turned to its Facebook page to complain. In response, Smucker's tried to take control of the situation by deleting the comments--and made the situation far worse.

9. LG's mockery of iPhones backfires

LG tried to make fun of Apple's #bendgate by tweeting from the LG France account that "Our smartphones don't bend, they are naturally curved ;)." The only problem: The tweet was sent from an iPhone.

10. McDonald's tries new mascot hashtag

McDonald's tried to celebrate the debut of a new version of its famous mascot with the hashtag #RonaldMcDonald. The plan backfired when nearly all of the responses on Twitter bashed the clown's makeover and the restaurant chain's food.