Unless you're playing the SNES game and you're a super-cybered-out shaman decker street sam who can dice a dragon, a lone runner WILL get geeked by the first gang he crosses.  Not to mention the megacorps.  At least, that's the way it seems to me.  I may have the wrong idea about SR, but still it's sound advice to find a few people you can TRUST to make up for the things you can't do.