We were in Vienna recently, and went to a restaurant at the Naschmarkt for dinner. Wanted to order Sturm, but this one did not have it, so just asked for tap water instead. Ordered a starter and a couple of main courses, and then asked for the check, and out pops a 2E charge against "Water". We asked the server what this was for, and she said that they charged for tap water!
Now, from our appearance, it was obvious that we were not from Vienna, and not being sure of what to do in this situation, and not wanting to create a scene over a couple of euro, we just paid. But I am curious to know whether we were just ripped off for being tourists or this is normal practice?