I often read and heard about burning tokens that were not sold when the ICO project was finished, I also knew that by burning the rest of the token was a strategy so the price of the token didn't fall, but if the DEV and the team didn't burn it was a crime? is there a requirement that the remaining unsold tokens must be burned?
I think that is one of the strategy to keep the value of a coins to be high, burning the token means it will reduce the total volume of the token itself.
With less volume, hopefully the price of a token will also rise or it can be keep in a good level of price and not making it drop.