People have their excuses, but you don't have to watermark the panels like this. The people who say it's necessary say it is because of aggregators removing credits and claiming things as their own.
Watermark or not, aggregators that want to will claim scanlations as their own anyway. :|
I once saw Mangapanda (or Manga
whatever, tons of them out there) steal and watermark Mangastream's work--after it was already stolen by another aggregator that marked it themselves. Therefore, that aforementioned excuse is invalid--stop watermarking panels. All of this is illegal, but at least have
some respect for the mangaka's work, which isn't just text.
I thought the watermark on the first content page was off, so I checked and they just ripped it off some other site and replaced the watermark :/
Maybe this is just another example of what I'm saying, then.