I don't know when and where this started, but it needs to stop. We have had alternatives to the mouse for a long time; we can no longer rely on the ability to use a cursor to indicate if a region of the screen will do something when clicked. In fact, we never should have relied on this ability.
Regions of the screen that are interactive should be visually distinct from those parts of the screen that are not interactive. If a user can't make this determination quickly and easily then it's possible that he will click something he thought was inactive and have it unexpectedly respond to his input (or vice versa). When this happens the user is going to become angry and irate and will transform into a very large dinosaur and will go back in time and devour the other, smaller dinosaurs which will completely disrupt the timeline.
Who knows what will happen if your users do this? It's a risk we just can't afford to take. So let's save history now, with this blog post. No more will we live in fear of the time-traveling saurian user. All we need to do is follow a very simple guideline: if it does something, make it distinct from its surroundings.
Let's start with examples of what I mean. Let's say you're looking at a website that has funny pictures on it. (That's roughly 45% of the Internet - the remainder is websites for other types of pictures.) The site shows some thumbnails which can be clicked to show the full-sized version of one of those most hilarious images you love so much (images of cats, statistically speaking).
Now imagine that you're using a touch screen monitor instead of a mouse when looking at these pictures. You mash your still-mammalian finger against some whitespace next to an image in order to make sure the browser window is in focus before moving your finger across the screen rapidly in the scrolling gesture. But wait — instead of activating the browser window you're instead shown the large version of an image near where you clicked. This image isn't all that funny; you didn't want to see this picture in its two million pixels of bland sedatedness! You become a dinosaur of rage. A rage-asaurus.
Surely no website would do this to our timeline, you might be thinking. Think again! This dystopian world I just described is the default behaviour of Blogger blogs. Some of your favourite blogs such as Cake Wrecks and the "Blog" of "unnecessary" quotation marks both propagate time-terrorizing tyranomen. Indeed, even some of my favourite blogs such as The Old New Thing do it as well (in this case, the whitespace to the right of each post's title is a link).
How this is accomplished using HTML is actually very simple: a link can be defined to have the width of its container, and then an image can be placed within that link. The result is a link that is wider than the image inside it. If the link is invisible, then the only way a user can avoid clicking it is the change in the cursor if the mouse is over it (assuming the cursor property isn't overridden in the page's CSS). Of course that breaks down completely when using a system that has no cursor (such as a touch screen), leaving us with prehistory undone.
For those readers not familiar with HTML or CSS, it is important to note that this is not the default behaviour of links around images. A plain old link around an image will contract to fit snugly around the image like a glove. It takes extra effort to make Blogger-like image links. That means someone, somewhere, has specifically decided that this is how things should be. It's not an accident. It's a purposeful, malicious attempt to destroy time.
Blogger's crusade against chronology isn't even the worst of it: this behaviour violates nearly every speck of usability common sense there is. Why would someone who presumably wants his content to be consumable by everyone — including those of us who have removed the separation between input and output devices — tie his design to a particular input method? The Web was designed to be ignorant of how its content is being displayed (if it's displayed at all) and to be ignorant of how it receives its input. By creating spaces on the page that are visually indistinct from their surroundings but whose behaviours are distinct from their surroundings, Blogger is assuming a particular type of input mechanism is being used and is therefore disregarding the fundamentals of the Web.
Such blatant transgressions have not gone unnoticed. As technology advances we're going to see many different types of interaction and Web frameworks like Blogger that assume specific types of interaction mechanisms will have to change or will no longer be used in whatever comes next. In the mean time, keep an eye out for raptors.