The "stop" secure action isn't really doing anything in that macro.
/cast Mocking Banner
/tar Mocking Banner
/cast [help] Intervene
If you have no target, a hostile target, a neutral target, or a friendly target not in the group, it will cast a mocking banner, then after it's placed, using the macro will intervene to the banner.
It only wigs out when you have a friendly target when casting the banner. Then it will cancel the banner, intervene to the friendly and then /targetlasttarget.
If you have an addon to support greater than 255 characters you can do something like:
/run if not DmI then
DmX self:SetAttribute("macrotext",DmX and "/cast Demoralizing Banner"
or "/cleartarget\n/tar Demoralizing Banner\n/cast [help]
Intervene\n/targetlasttarget [help]")]]) end
To make it more reliable with friendly targets, but macro sequences like this can't be reset so it's a toggle kinda: alternately cast a banner and attempt to intervene to it.
Edited by Ro on 10/1/2012 3:57 PM PDT