Note: When using this in class, you will have to set some ground rules, because some students will want to post silly things. The way to counter that is to set up the activity well. Explain why you are using this tool, what your expectations are, what the rules for its use are. I have had varying degrees of success: It worked really well in a Year 7 and a Year 12 class. Not as well in a Year 9 class, but that could have been because I did not set the activity up very well, and the use of this tool was just a bit too gimmicky.