Should we be worried about new Immigration rules in Thailand ?
The answer is generally not despite rumors that next month, tourists and expats can not present their passports at any time be thrown into prison and sentenced to a fine THB20, 000. Immigration colonel says it is incorrect.

“Making all foreigners in Thailand carry their original passports with them would be very difficult,” said police Col. Voravat Amornvivat. “It’s about being reasonable and using common sense.”
A much more moderate comment than the comments attributed to the same Voravat in an article published in the press. Neither tourists or expatriates will need to keep their passports on them at all times, added Voravat, but they must have an ID paper and be prepared to recover their original passport if requested.
Immigration has tightened its sanctions with new penalties including long term entry on Thai territory ban for those who overstay their visas.
In summary, it is advisable anyway to have your passport on you as often as possible when traveling in Thailand, or at least to have a copy. As for the fine, it probably won’t apply, the prison sentence neither. It would be destructive to the tourism and annihilate all the efforts to recover tourists’ confidence.