Yes, some might be diverted by ISIS but, if made with coordination with inside elements, could mainly be found and kept by civilians.
And I have the nagging impression they would strongly protest if it was America or any "Western" poser sieging a city.
This poster is a supporter of the far-left "peace organization" the Stop The War Coalition. The principal actors in the STWC supported this kind of ghoulery in Sarajevo, Kosovo, and Eastern Ukraine, and now Syria. This quote is just a smidgen away from the quote people like xxyx love to repeat about Ben Tre that shows how evil the West is: "It became necessary to destroy the town in order to save it." At least the US admitted its part in Ben Tre. As for Aleppo, xxyx and the STWC will do just what they've done with Srebrenica, Recak, Rwanda and all those other occasions when they've backed bloody tyrants because their victims have had the misfortune to receive Western sympathy: they'll simply deny it ever happened.
The point about Stop the War Coalition is made, in a larger form, by Ian Birrell in [i]Why will Stop the War not condemn Russia?[/i].
In short, like Pink Code in America, which protests against attacks against ISIS, or the folks who protested against the Euromissiles, they're more anti-"West" than anti-war.
The worrying point is that the leader of one of the main political parties of a major country is the founder of the outfit.
If that's their position, it's lazy, weighed down with moral cowardice, and combined with a studied indifference to the suffering of others.
The outcome isn't peace at all, but simple, fragile stasis maintained through a government's willingness to control its civilian population with terror.
And this isn't like such status quo might last forever: the amount of repression materially useable is limited, and the day where no repression could be used against resistence is usually the downfall of the regime.
This is why the Fragile States Index has worse notations for states with dictatorships, one-party states and any states where brutal force is used to quell opposition: one day, like with Siad Barre, Kadhafi and Mobutu, the while rotten structure might collapse.