But when it comes to medical advice, a new study shows that such sites can be the source of potentially dangerous misinformation for millions of people.
A new study in the American Journal of Infection Control shows that over a four-month period in 2009, hundreds of Twitter users posted casual misinformation about antibiotics -- which, in turn, reached more than a million of their followers.
"When we looked at tweets ... we found that there are some basic categories like general mentioning of antibiotics or complaints about side effects and things like that, but there was also a category that was pretty interesting, where people were indicating misuse or misunderstanding of antibiotics," study co-author Daniel Scanfeld told "Good Morning America."
"And we found that to be really interesting, because one tweet indicating misuse of antibiotics could be spread potentially to hundreds of thousands of people via the Twitter network."
While overall around 2 percent of the studied tweets contained misinformation, Scanfield said that even a single inaccurate tweet is broadcast on average to "tens of thousands of people."
For example, Scanfeld said one tweet about antibiotics for a cold -- which is not their intended use -- reached around 850,000 people. In other cases, the study found people often tweeted about not finishing their antibiotics or offering to share them with others, a big no-no when it comes to medications.
How to Avoid Misinformation on the Web
Tip 1: Confirm All Medical Information With Reputable Source
It's fine to look online for answers to medical questions, but it's crucial to verify what you find with a reputable source, such as your doctor.
Tip 2: Be Wary of Any Posting That's Selling Something
Be extra cautious if any postings or tweets are selling something. Some product claims have no basis in reality.
Tip 3: Know the Source
Take a look at the Web site ending. Remember that ".com" Web sites are for-profit, ".edu" are educational sites and ".gov" are from the government. Many disease specific Web sites or medical association Web sites are ".org". Get to know a few sites and bookmark them so you can go back easily.
Tip 4: Check Legitimate Web Resources
Some online resources can be good sources for basic information you can consult in addition to talking with your doctor.