Lydy's Anarchist Revival Meeting

From the information you have provided, it seems unlikely (to me anyway) that your colleagues are deliberately stealing from you. If all the silverware disappeared at once, or one place setting at a time over a period of weeks, it could be someone who just decided this was a good way to furnish their kitchen drawers. But random disappearance of one item at a time (and mostly spoons, the item that is both smallest and most commonly used for coffee breaks) it sounds more like people being persistently careless. Still annoying, of course.