These \ (and $) thingies are placed in what we call "the fringe". And sadly, Emacs does not currently let you control the fringe when running in text mode. I think the answer pointed out by Angus is "the best we have" so far.
OTOH, for your specific problem, other than running Emacs in GUI mode, you might be able to let Emacs communicate directly with your desktop's clipboard (rather than let the terminal emulator), which then solves this problem as well as letting you copy text even if it's not displayed.
There is the xclip.el
package for that under X11, and someone has posted a patch (not yet integrated) to make it work under Mac OS X as well.