well, currently users are able to EDIT their post which might result into confusion when the specific text is being changed (e.g. 3 days after the original post). This might also get into bad behavior/cheating, etc. and other risks when people are able to completely change their content later on (maybe to something totally different in context or meaning). I would suggest of setting a Time-Limit as to which posts/comments are allowed being altered (e.g. 1 hour).