Despite the debatable religious motivation, they are selflessly delivering "true grace" to the dead terror victims. The organization has never made political statements, and as far as I know, is not affiliated with any political party. Every TV broadcast from a terror bombing scene includes the XSE volunteers, in fluorescent vests and long beards, scooping up body parts and personal belongings into little bags, carrying corpses onto stretchers, etc.
A small news item on ynet (Hebrew) this morning reports that two XSE containers full of equipment were stolen in Jerusalem.
update: gaal was reminded of an older article about the XSE folks, that proves that they have been political, or at least that Yehuda Meshi-Zahav, an ultra-orthodox "field" leader, is involved with them, and that during the so-called "Defensive Wall" operation, the XSE people, like at least one hospital, showcased the bodies to the TV cameras, to emphasize the heinousness of "the Palestinians" (and not "the Palestinian terrorists"), thereby contributing to the rabid demonization of the Palestinian public in Israel in those days. This is reported in this Hebrew Ha'aretz item (regrettably, the web page itself only shows the current date, but gaal and I discussed the item in April 14th, so it must have been published then or a day before). That's deplorable, and Meshi-Zahav is a despicable man. But still, most of the volunteers just do their work, and I would not care to trade places with them.
And stealing their equipment is very, very low.