"Junya Yimprasert left Thailand in 2010 and now lives in Europe. She has been campaigning to showcase what she sees as the monarchy's grave failings for years.
She told DW that as Thailand's head of state, King Vajiralongkorn shouldn't be conducting official business from abroad.
"The Thai people are getting angrier because he is not in Germany just as a tourist and hasn't stopped intervening in Thai politics," she said. "He is here in Germany and continues to have influence."
The protests have grown over the last few days and things are getting tense in Bangkok.