We tend to think of Facebook and Twitter as safe places to keep up with friends and family, but, as it turns out, even these 'friendly' sites and apps can be risky.

According to WatchGuard security researchers, even the seemingly harmless social media sites can bring hackers. Here are some of the worst offenders.

Facebook: Facebook is the most dangerous social media site today, mainly because everybody and his brother uses the popular site. With that many people using the site, you have to assume that they are not all there to post pictures of what they had for breakfast.

Twitter: Many people find it hard to say what they want to say using only 140 characters. Well, you can depend on this; plenty of people know how to hide malicious links using less than 140 characters.

YouTube: Oh, good. A 'rare' video of The Beatles eating a tuna sandwich -- It's so easy to hide malicious links in these videos that just about anyone can do it. Be super careful when watching the Beatles eat that tuna sandwich.

LinkedIn: Linkedln is basically a business oriented site. Hackers love business oriented sites. Let's face it, people get comfortable with sites like Linkedln and may be sharing business information with people whose business it is to get into your business. Did I say that clumsily enough?

4chan: Just stay away from this one all together. It's rife with hackers.

Chatroulette:  Chatroulette is an up-and-coming site that allows webcam owners to connect and chat with random people. Sounds great until you consider that it's a favorite among predators. Another good one to avoid all the way around.