The Dutch government is coming down hard on foreign operators who are breaching their laws. As they are opening up the market for foreign licensees in 2016, they are imposing fines on casinos who are openly targeting The Netherlands before the licence-system is in place.
Now, as long as your website is in English there is no problem accepting Dutch customers. Should you however offer your website in Dutch, you could be in for a nasty surprise. The Maltese operator and Netent casino ComeOn noticed this as they recently got slapped with a fine of 180 000 euro on behalf of the Dutch government and gambling regulator Kansspelautoriteit.
Comeon.com had allegedely offered their website with a Dutch-language option, with Dutch live-chat option and even with a Dutch-flag. This enraged the Dutch lawmen who previously have fined 7red.com and Rooyal Casino.
So the moral of the story: You are fine to target Dutch players, but just do it discreetely.