[5] In April 2010, de Winter was involved in the disclosure of the expenditure of the FENS funds (1.3 billion euros) by the NS.

Due to the disclosure, the District Attorney decided to open a criminal investigation against de Winter; however,[9] after a legal defence fund met its goals within an hour.

The articles written by him focus on the business side of the IT industry and the technical aspects of open source software and IT security.

De Winter issued a WOB request to the Dutch Association of Municipalities (VNG) to gain more insight into the performance.

When the VNG refused to make the information public, de Winter filed a lawsuit,[15] and later, WOB requests to all individual municipalities, provinces, and many independent administrative bodies.

Winter was on 16 December 2009 at the presentation of the Book A wall of rubber in the WOB in journalistic practice for to criticism from the parliamentarian Pierre Heijnen (PvdA).

Winter by the Public Prosecutor considered suspicious for manipulating value cards, possession of means to do so, and computer intrusion.

In demonstrating the weaknesses were also journalists, among others, the NIS, the public broadcasting Powned, Computerworld, RTV Rijnmond was involved.

Moreover, in this case considered important in that de Winter, a professional journalist, exposed the vulnerability of the smartcard and was criminally investigated for fraud by the request of the corporation associated with the card.