Hey there! Hello!
For this question, I'm not sure if you have multiple choice answers; if you do and my answer doesn't really fit into any of them, let me know and we'll take it from there.
Putting anything on the internet can pretty much guarantee that it will stay on the internet forever. Someone, whether it be someone who saved/screenshot your post or the service that controls the posts of the website saving a copy of it and all other posts, it's impossible to get rid of all remnants of a post once you have posted it. Think of all the people who may have reblogged/retweeted/re-whatevered a post on a service that supports it, too.
Most social networks put in their Terms and Conditions that they are allowed to see any and all of what anyone posts or sends to someone through their service. If you DM your significant other a picture of you that you wouldn't want your mom to see, the social service then has the right to view and save information related to the post for quality/functionality/ whatever other reasons. Social services usually have the right to save copies of any information you give to them, whether it be your name/email address or a credit card, for advertising/other purposes.
Also keep in mind that caches exist. The entire purpose of Google Cache is to dig up HTML's from old websites that don't exist anymore for the purposes of allowing someone to view their beauty once more.
Point is, you can burn papers and the information that they held, as long as it wasn't copies and distributed, will be gone. But it's not exactly possible to burn deep-rooted information in the internet's servers that may not be accessible to you once you have deleted your copy of it, but very much accessible to anyone with the expertise to dig it out.
Hope this helped you out! Feel free to ask any additional questions if you have any. :-)
