Social media has been around since the campfire, the original social network. Sure, technology has created new opportunities but the fundamentals haven't changed. We've been lying, cheating and stealing for thousands of years and laws have been codified to deal with it.
So, social media law is nothing different. The laws in place to cover those ancient misdeeds still apply. What is different is HOW we are screwing each other over. The technology gives ways to harm people while (supposedly) anonymous, remote and even automatically.
Thus, the law needs to keep up. Either through legislation or (more likely) court rulings, every new social media illegal activity has to determined. And it's not an easy task. Multiple jurisdictions, overlapping laws, different vendors, as well as complex technical issues all add to slowing the development of social media law. It's a race where technology seems to be always ahead. Luckily, the Law is ever persistent, and each new loophole gets closed one by one.
In the US, there are two overriding Laws that govern social media networks; Section 512(c) of the Digital Millenium Copyright Act and Section 230 of the Communications Decency Act. Here are the most relevant sections:
(c) Information Residing on Systems or Networks At Direction of Users.
(i) does not have actual knowledge that the material or an activity using the material on the system or network is infringing;
(ii) in the absence of such actual knowledge, is not aware of facts or circumstances from which infringing activity is apparent; or
(iii) upon obtaining such knowledge or awareness, acts expeditiously to remove, or disable access to, the material;
(B) does not receive a financial benefit directly attributable to the infringing activity, in a case in which the service provider has the right and ability to control such activity; and
(C) upon notification of claimed infringement as described in paragraph (3), responds expeditiously to remove, or disable access to, the material that is claimed to be infringing or to be the subject of infringing activity.
Section 230 Communications Decency Act
(1) Treatment of publisher or speaker
No provider or user of an interactive computer service shall be treated as the publisher or speaker of any information provided by another information content provider.
(2) Civil liability
No provider or user of an interactive computer service shall be held liable on account of—
(A) any action voluntarily taken in good faith to restrict access to or availability of material that the provider or user considers to be obscene, lewd, lascivious, filthy, excessively violent, harassing, or otherwise objectionable, whether or not such material is constitutionally protected; or
(B) any action taken to enable or make available to information content providers or others the technical means to restrict access to material described in paragraph (1). 
(d) Obligations of interactive computer service
A provider of interactive computer service shall, at the time of entering an agreement with a customer for the provision of interactive computer service and in a manner deemed appropriate by the provider, notify such customer that parental control protections (such as computer hardware, software, or filtering services) are commercially available that may assist the customer in limiting access to material that is harmful to minors. Such notice shall identify, or provide the customer with access to information identifying, current providers of such protections.
These laws, taken together, have enabled the flourishing of social media. Without these Laws in place, any post or tweet could hold the network itself responsible for the content. And as so much nefarious content is posted the legal implications would be a death knell for the industry.
How about for the users? What laws protect us? These laws refer to the social network provider so don't offer any protections for consumers. We post at our risk. Existing laws apply, so we need to consider them before posting anything that might warrant action.
The most likely offenses are defamation and infringement. Both, however, have possible Constitutional protections as regarding free speech. Unfortunately, as with any free speech arguments, many times it's a case by case situation, so there is no clear cut law. The range of communications is too broad to cover all scenarios fully.
As with most social things it comes down to some common sense, politeness, and empathy. In regards to defamation, would you say it to their face? If not, why would you say it online? It could be considered worse as it's public and is permanently recorded.
For infringement, it comes down to the amount of offending content and the credit. If you use a small section of material and provide a quote, citation or link you'll probably be fine. If, on the other hand, you use large sections of content without attribution then you're probably over the line.
The golden rule still applies; treat others online as you want to be treated. If you HAVE been mistreated, then make sure that you collect and preserve the social media evidence so that you can take action.
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[header_fancy class="header1" style="margin-bottom: 20px;" text="WebPreserver"]
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