Under martial Law any assembly of more than five people was banned, and as far as I know it is still under the new Section 44 rule. The current government aka junta doesn't like protests much. The more I was surprised to see a large gathering of people this morning in front of the US Embassy. Police was just arriving, apparently surprised.
Facebook page and a website full of information.
Major concerns of the environmental activists are poisoning of rivers with chemicals as well as a threat to other water resources. Pictures are taken already show dead fish, but I couldn't understand the whole context of the page since it is in Thai and my knowledge is only limited.
Police was just assuring traffic flow, while quite a lot of reporters including TV crews were interviewing the protestors. The activists submitted a letter and then went home.
Smart move to blame the US for it to be legally safe while at the same time raising the issue :-)
UPDATE: In todays Bangkok Post Puangthip Silpasart, director-general of the Ministry of Energy's Department of Mineral Fuels (DMF), denied that oil exploration projects in the Northeast are using fracking technology or hazardous chemicals.