In 2011, Van Erp became involved with Stichting Skepsis, where he has served as board member since March 2012 [REF].
In 2015 and 2016, Van Erp spoke at several meetings of Freethinkers and Skeptics in the Pub in both the Netherlands and Belgium, including the cities of Ghent (about Wim Hof, beach-protecting tubes and the ADE 651 fake bomb detector),[REF][REF] Amsterdam (on climate change denial)[REF] and Nijmegen (on ufology) [REF].