I don't know where to start with this.
Just because you don't like embedded images Theymos, does not mean that you get to speak for everyone on this forum. There are plenty of means by which all of the technical issues with externally hosted images you have mentioned can be addressed. There are ways of banning dynamic images, preventing cookie stuffing and preventing large unsightly images.
The argument about images taking up online 'real estate' is the weakest I have heard - as if it were limited in some way or in short supply.
The purpose of this forum is to provide a place where ideas can be expressed and consumed with as much freedom as possible. I have determined that the best way of facilitating this goal is to disallow embedded images.
YOU have determined. With no consultation with the rest of the users on this forum. So the best way to ensure ideas can be expressed effectively is to unilaterally ban any form of imagery and limit people's means of communication to text only? This is broken logic.
Signature images are never useful in exchanging ideas. They never contribute anything to the discussion at hand. Maybe they help you understand the poster better, but understanding posters is not the point of most threads. Signature images are off-topic in almost every thread they appear in.
You say that they are never useful, but then go on to shoot your own argument in the foot. Sig images can help you get a better idea of who the person behind the text actually is, thus modifying your preconceptions of the poster and his post. The argument about them being off topic is moot. They were never supposed to be on-topic as they are not part of the thread itself. They are signatures.
This is often also true of embedded images in general. I would estimate that half of all images posted recently are totally off-topic, and perhaps only a tenth contribute significantly to the discussion. Many images are somewhat on-topic and useful, but they take up more space than they're worth.
Text can also be off-topic (both in signatures and out), but text takes up much less space, and it's less distracting.
You are making huge assumptions. How can they take up more space than they are worth?
There is no end to the amount of space that a thread can take up.
How can you judge their worth anyway?
And like you said, text can also be off topic. Why not ban all the text aswell?
Oh, because it's smaller and less distracting! I see.
We are not all that easily distracted.
There are also security problems: Images can be used to execute cookie stuffing and cross-site request forgery attacks; they use a lot of bandwidth; and they prevent bitcointalk.org's HTTPS from appearing totally "kosher" to browsers. These issues could be solved by hosting all images at bitcointalk.org, but this isn't worth the trouble.
Yes, hosting the images is not worth the trouble. Definitely don't do that.
But there are many ways you can prevent the linking of dynamic images, and thus prevent cookie stuffing.
They do NOT use up any of this server's bandwidth. Are you kidding me? The request is not sent from this server, it is sent from the users viewing the images - using up the bandwidth the image is hosted on, not bitcointalk's bandwidth.
I never get HTTPs errors. Never. Using safari, firefox or chrome.
Turn down the fidelity of your browser's error reporting if it's a problem for you.
Yes, users can block images in their browsers. But it seems to me most correct to assume that users don't want something possibly unwanted than to assume they do want it. Posts are categorized so that readers have a choice in what they read. I want images to be placed, along with all other non-textual data, into a category that requires an extra choice on the part of readers.
Why not hold a vote on the issue to find out how correct your assumptions are?
I really don't mean any offense to you Theymos, or to any of the Admin or Mod team. I think you do a great job and I know from past experience of being a forum administrator that it is a thankless job. But this is silly, and I think most would agree that this seems like an over-reaction to something that is only a MILD annoyance at best. I think this is a terrible idea for the vitality of this community.
If we want to ensure a platform for free expression, then people should be allowed to express themselves freely and not be restricted by totalitarian bans on imagery. If you are unwilling or incapable of addressing the technical issues, then you should hire someone to do it for you or step down in favor of someone who is capable.
A text-only forum in 2011? I can't believe we are even having this discussion.