One of the most common crimes being committed online and in the world of social media is theft of content. Sure, most content is provided for others to consume and in many cases, for us to use and reuse if we want. But more times than not, proper credit is not given to the content creators.
The easiest answer is to always create your own content so that you do not run into problems with plagiarism. Secondly, if you use ideas and content from other sources, obtain permission first. Past that, you could use a service such as Pagtracker, a Free Plagirism Checker.