So, where exactly are you letting the children drive the bicycle ?

In teh garden ?
Any road is dangerous. I remember one gf I had, her parents were so obsesed with security that she grew up without knowing to sweam, drive a bicycle and many other things.
You are missing the point. I am not discussing if it is possible to cause damage on the forum. It certanly is, in any system. I can, for instance, create automatition script that will totaly destroy any forum by makint it unusable; in order to achieve that, I would automate browser using COM, WebBrowser control and JavaScript; the script can do anything automaticaly, like spamming indefinitely in a very short frequency, using a proxy list so you can't ban the IP, registering eventualy new user each time, doing OCR to recognise captcha etc... All of those things are already done, just not that way

That m8 was kind enough to tell you that forum software u use is vunarable, but any software is if you know it enough. PHPBB forum was once attacked by some islamic fundamentalists who deleted more then 100 forums they found vunarable leaving only 1 message in them, and some a-la matrix scrolling animation. Your Windows is vunarable as switcherland cheeze. Your *nx distribution also, especialy due to the open-source factor (the reason some GOV institutions have their own distributinos). So, really, if I am willing enough, and motivated enough I can do anything.
All in all, I think IMG tag is safe to use. It will make this place less dull as of "1 picture tells more then 1000 words". I hope you are keeping backup of this forum in case bastard shows up
Anyway, its not THAT important. I get used to have pictures on forums, but I can leave without them. I am just telling you what I think about it.