Here’s a theory why Iraqis might hold up signs calling Human Shields ‘wankers’, straight from the horse’s mouth. Salam Pax:

What really got my goat this time was finding out that they get food coupons worth 15,000 dinars per meal, 3 for every day. Fifteen thousand. Do you know how much the monthly food ration for a 4 person family is worth, for a whole month not per meal (real cost, not subsidized)? 30,000 dinars, if you get someone to buy the bad rice they give you for a decent price. 15,000. What are they eating? A whole lamb every meal?

Of course, wankers being such a curious word, unless you regularly dabble in en-gb, it’s also possible that particular sign may have been made up by a (British) human shield as a last sign of defiance, but was co-opted into a Iraqi quickie demonstration.