Hi @roelandp, in #Hive we usually inculcate the good use of the platform, I don't want to accuse you of anything as I also write post and sometimes I forget to give credits, something as simple as placing the source from which I got an image, I want to believe that in the speed of writing your post you forgot the detail, but for sillier things than this @hivewatchers has muted hundreds of post.
7 Intellectual property rights.
Attribution.
Do I have to include credits on photos? You do not have to include credits on photographs for commercial use, but if you are using the content for editorial purposes, you must include the following credit next to the content or visual production credits: "iStock.com/Artist Name".
Also from the same iStock website
You are free to use the watermarked content from the iStock site free of charge only for use (in composite form) as a proof or sample mockup. The watermarked content may not be used in any final material or any publicly available material, and may only be used for 30 days after download.
It's not a matter of opening a debate, arguing or anything like that, your post is simply trending, it's being seen by thousands and details like this should be avoided.