Copyright

So copyright issues. One of the biggest things around. Normally copyright laws would be simple. You took the picture so therefore its your right? but oh so wrong when it comes to social media. Generally when you post a picture on a social media site you are agreeing that you give the site permission to use your photo, so is the photo really yours anymore? That would be no.
It's really the same as anywhere, people upload something they have created and sometimes other 'steal' it. It's really hard to maintain what is copyright when it comes to these sites, with all the multiple sharing and reposting.
You should really acknowledge the person that created the item if you are going to re-post it. For example a lot of fan artists create drawings and artworks and post them on Tumblr, where many people then share those pictures around because they are fabulous. But sometimes someone will share the picture and claim it as theirs. It can be really hard to say hey that's not yours it mine because it's everywhere on the internet. So remember if you're going to share something on social media, that you are sharing with the whole world too. And give credit to those who are the ones creating.