Gemany, as you likely know, has much tighter restrictions on weapons than in the United States. In most cases, guns are only permitted for hunting or shooting sport usage, with limits on the type of guns allowed, and with further requirements such as passing the hunter’s exam or being an active member of a shooting club. Carrying a weapon for self-defense is permitted only for cases of demonstrated need, e.g., private security personnel or individuals under a particular threat. (See wikipedia for the particulars.)
But there’s one type of weapon that’s widely permitted: “small firearms,” that is, gas pistols (of the type that fire tear gas) or flare guns, require only the “kleinen Waffenschein” or “small arms carry permit.”
And, according to the facebook page of the Cologne police, and as reported by Der Spiegel, they’re receiving unusually many new applications — and posted an instruction to the public that such a permit has to be applied for at the applicant’s hometown, not in Cologne itself if they’re not resident there, and they’re notifying the public to reduce the workload of city officials.
Which, if nothing else, speaks to the worry that Germans have for their personal safety.