Underwater Images - are they being stolen?

The other day I was doing a search on twitter for "underwater photography", and I noticed something interesting. The most popular results were for titles like "10 amazing underwater photos", "50 best underwater photographs", and "20 stunning underwater images".

The reason that they were popular was because people quickly "retweeted them", which means they passed on the link to their twitter followers.

Now twitter only gives results for the past few days, so if you do this search today you may see different results, but I think you know what I'm talking about. This is not only particular to underwater images, it happens with all images.

After checking the links, I made the following observations: 

• Most people who passed on these links were not in the photography or the underwater industry
• Although many of the images were good, they were usually not what I would consider the "Best" images, although they would generally be considered beautiful to the average person.
• They always appeared on blogs that had heavy advertising, often in countries known for lax copyright enforcement. These blogs were clearly not for "non-commercial" use - their sole goal was to make money via advertising or selling a product.
• It was not clear if the blogger got permission to post the images from the photographer. My guess is they didn't, but I can't be sure.
• Often, but not always, the images were from Flickr, where people said images could be used only for "non-commercial" use, or they had all rights reserved.
• One United States based web-magazine did make sure they only used photos from Flickr that used the "creative commons" license, and they gave proper attribution. But they seemed to be the exception, not the rule.

So what does everyone else thing about this? Is it considered stealing the images for the blog's benefit? Or is it an acceptable and legal use of the images?

If your image was used without permission, would you feel honored, or would you feel it was copyright infringement?

I look forward to hearing your thoughts in the comments below.

Here's a couple examples:

http://creativefan.com/25-breathtaking-underwater-photographs/

http://naldzgraphics.net/inspirations/showcase-of-excellent-underwater-photography/

I was not sure whether I should post these links, but I knew that people would want to see examples. These links are no-followed so they are not getting any SEO benefit. I'm not claiming that these blogs are doing anything wrong, but they might be - I want to see what you think.