i think can be used to inject html to some extent.
in the sense that it causes HTML tags to be added? then sure. it literally does nothing but put the contents in a <tt></tt> tag. if you see that as a problem then so is bold, italic, underline, strikethrough, alignment, horizontal rule, size, color, image......
[tt] isn't vitally important though:
[pre] does nearly the same thing
but creates a new block, which is why it looks like there's a line break after it, but if you quote this post, you will actually see there wasn't. if that messes with your formatting then just use [font=monospace].
it's a little more cumbersome, but it does precisely the same thing that [tt] doesall the people using the exploit were using which i guess aided in loving up the formatting.
no, it didn't. at most, some fools might've gotten it confused with the actual table tags