I'm referring to Known Image Restrictions - Places and Landmarks - Europe and Africa https://support.submit.shutterstock.com/s/article/Known-Image-Restrictions-Places-and-Landmarks-Europe-and-Africa?language=en_US

It looks like other sites don't care about this? For example "Blenheim Palace" is restricted for SS, but plenty of images on Dreamstime?

Any experience?

I'm referring to Known Image Restrictions - Places and Landmarks - Europe and Africa https://support.submit.shutterstock.com/s/article/Known-Image-Restrictions-Places-and-Landmarks-Europe-and-Africa?language=en_US

It looks like other sites don't care about this? For example "Blenheim Palace" is restricted for SS, but plenty of images on Dreamstime?

Any experience?

iS has a list, available to contributors, of sites and things it won't accept because of legal restrictions or perceived legal restrictions.
Historically, SS was laxer; perhaps they're catching up.

Bu what if the property owner finds my photos, let say of Dreamstime? Will I be in trouble or Dreamstime?

It's still tempting. They have 100+ sales!

Every agency will pass on legal problems to the contributors.

Personally, I would never take the risk for the few dollars. When I see how many images are accepted for commercial use that should never have been accepted, I wonder a lot. Be it Apple, Harley Davidson, the Atomium in Brussels, the Sydney Opera, Gehry buildings or whatever.

Just FYI: the Atomium in Brussels should be suitable for Editorial content:
https://wiki.gettyimages.com/atomium/
The Belgian government lifted those restrictions some years ago if I'm not mistaken.

Still, interesting discussion, and sometimes also a bit puzzled about what is allowed and what not and what possible consequences could be.
 
I've sold airplane wingtips with brands as editorial content, but if I'm not mistaken, this is not really allowed too, as it was during a flight where I paid for the ticket, right?
I've sold images of a both commercially as editorially restricted landmark. I didn't realize at the time of uploading, and agencies accepted the images. I removed the images once I found out, but one sold for ~200$ with a print license on Alamy. It was years ago. It were detail shots of specific architecture specifications of the landmark, but still... the landmark was named in the description and I guess I should never have uploaded those images for sale as I didn't had press credentials. 
I've sold images of crowds during a rock festival, which I paid a ticket for. I kept description and keywords generic, without naming the festival, and avoided logo's or brand references of the festival in the frame, but a pixel peeper can probably trace back the location of the photo.

I see a lot of content like that. Images of museums, artwork, restricted landmarks and so forth. Maybe some of them have press credentials or releases, but hard to imagine that all of them have them. The content I uploaded accidentally went through on most agencies, and the only agency being very strict on that seems to be iStock/Getty. They are pretty much on par when it comes to rejecting content like that, or afterwards removing content that was accepted previously.

I had uploaded a few photos from the "Nord Art" as editorials. They were accepted. On the same day I deleted them again. After a phone call, I learned that only certain photographers were allowed to take photos for editorial purposes there.

In Germany, the warning costs are usually $1700 to $2000. How often do I have to sell a picture to take the risk?

To stay with the Apple example: With Apple � as with many other manufacturers � it is not only about the logo, but also about the protected product design. Even vectors of it are prohibited.

https://helpx.adobe.com/stock/contributor/help/known-image-restrictions.html#design-ip

If you now enter "apple computer" as a search term and select "commercial" as a filter, you will receive thousands of images with clearly recognizable Apple products. As long as Apple tolerates this, because they are happy about this kind of product advertising, everything is fine. However, if Apple gets the idea to no longer tolerate this, it will hail warnings. And because the contributors even have the word Apple in the keywords, the search is particularly easy.

https://stock.adobe.com/de/search?filters%5Bcontent_type%3Aphoto%5D=1&filters%5Bcontent_type%3Aillustration%5D=1&filters%5Bcontent_type%3Azip_vector%5D=1&filters%5Bcontent_type%3Avideo%5D=1&filters%5Bcontent_type%3Atemplate%5D=1&filters%5Bcontent_type%3A3d%5D=1&filters%5Bcontent_type%3Aaudio%5D=0&filters%5Binclude_stock_enterprise%5D=0&filters%5Bis_editorial%5D=0&filters%5Bfree_collection%5D=0&filters%5Bcontent_type%3Aimage%5D=1&filters%5Billustrative%5D=exclude&k=apple+computer&order=relevance&safe_search=1&search_type=filter-select&get_facets=1

I once created a nearly photorealistic Apple keyboard as a vector file. But I never dared to upload it afterwards. It's just too risky from my point of view.

I agree with Firn and Wilm there, you should exercise some caution and know what you are doing. There are a few faux pas lurking here and you can�t rely on the agencies.

I myself had once made pictures in an archaeological park of Roman ruins in Germany.
Actually, I assumed that you can at least use the pictures editorially and all pictures were accepted.
But I was a bit puzzled by the fact that the agencies had not yet received a single picture from this park.

After a search it came out that the operators claim the photo rights completely for themselves and prohibit even the editorial use. At least one photographer has already been warned by a lawyer.

It's still tempting. Look at this https://www.dreamstime.com/stock-images-eiffel-tower-night-light-paris-france-image20029204
192 downloads, but it's prohibited on SS and Adobe.

It�s labelled as Editorial.