Then Daniel revealed what the writing said to the king. He told him that his reign of king was over because he raised himself up against God and worshipped the idols. He had not done what was right before God. The king died that very day and someone else took over his kingdom. God will only allow so much, then he will say "enough." God is merciful, but there were times when God had to pronounce judgement.
This world of ours will not be exempt. People are indulging in every sin imaginable, but God will not let it go on forever. He will bring judgement. When He does, people will be petrified, just like Belshazzar. Rev 6:16 tells us that there will come a time when people will cry for the rocks and the mountains to fall on them to hide from the face of God. Be sure your life is right with God and you will not have to fear His judgement.