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?
Unless stated, It is not a requirement to burn unsold tokens but it helps boost investors confidence that the team will not dump those tokens on the market. There is also that belief that a lesser supply will help boost the price.
But most of the bounty hunters still dump the price of it, even if they burn it. Face it, but that is the common process when the ICO done.
By not burning some tokens is not a crime, because those thing is optional for the team except they stated it from the start. Also, I don't see evidence when the token is burn ( don't have idea about what process they used to be ) .