If somebody disclose their Pub-ID, what will happen? Is it against google's adsense TOS? I've read their TOS but didn't found anything about this.
Not specifically against the TOS, no. Anyone can find your pub ID just by right clicking your ads. To prevent your pub ID being abused be sure to add all of your sites to your 'Approved Sites' list in your AdSense account settings.
no issues with that...you can post your pub-id but google cops wont catch you!!! so..enjoy...dont worry!!