I find it hard to believe. Stamps can at most tell about your general location but can never be specific enough for artillery "邮票泄密 二战期间,法国炮兵排长腓力每天给妻子去一封信,并叮嘱妻子不可将他的驻地告诉任何人。妻子一女友是德国间谍,以集邮为名,揭去他每次来信的邮票。后来,腓力写信说:“半月中我们换了5次阵地,而敌人大炮总能跟踪射击,部队伤亡很大,我也身负重伤……”