Border runs (getting out and in of Thailand and stay for a long time on an exemption of visa) were already a thing of the past, but now it’s getting even tougher, to the point that only two entries par year on a visa exemption will be allowed at a land border. The new regulation came into effect on December 1st and aims at getting rid of foreigners who work illegally in Thailand. But as usual there will be some collateral damages, for instance foreigners who live in Laos or other bordering countries and who like to come shopping in Thailand won’t probably bother to apply for a visa each time.
For further reading: http://www.bangkokpost.com/news/general/1256835/new-visa-rule-for-land-arrivals-hitting-singaporean-visitors