While I think the popularity of it in such contexts came about after this page was published, I'd also add "Useless use of dd": the application of dd to do a non-transformative copy to or from device files.
In Unix, "everything is a file" means that even hardware devices are accessible using standard file APIs, and as such, doing procedures like "cp debian.iso /dev/sdg" to write out a USB device with a bootable ISO image is perfectly valid. One could even use "cat debian.iso > /dev/sdg" if desired, though the command doesn't quite convey the same meaning as cp, nor is it a concatenate operation.
In the 21st century however, it has become popular to use "dd if=debian.iso of=/dev/sdg" instead, and for the best I can tell, I think it stems from former DOS and Windows users, that make the assumption that hardware devices are special and require special programs to access, and somehow landed on dd being the special tool. Even though dd is really meant for transformative copies -- the program was originally written to convert documents between ASCII and EBCDIC! Worse than that, too, is that dd's mechanism of reading in and writing out in fixed-size blocks means that it's often much slower than just using cp.
Contrary to cp, dd can report progress (status=progress switch)
You could use pv, which I think gives a much better progress bar.