The eight members are accused of wrongdoing for joining a rally at the start of the “We Walk” campaign earlier this month.
The march was launched to raise public awareness about welfare programmes, universal healthcare, food security, community rights and environment protection, and political rights and democracy.
Alexander Nowak, a diplomat at the German Embassy, also went to Klong Luang Police Station on Wednesday to see what police planned to do in regards to the We Walk participants.
“I can’t see what is illegal about people walking. It is freedom of movement, freedom of expression. So I want to find out from the police about this summons,” Nowak said.