Strange is defined as being "unusual or surprising in a way that is unsettling or hard to understand". In this these cases, that is certainly so. Most can understand addictions to certain food, cigarettes, gambling, drugs and alcohol because these "normal" addictions bring certain "benefits" to the addicts. All has physical effects and psychological effects. Addiction can also be defined as "the condition of being habitually or compulsively occupied with or involved in something".
The common thing with both "normal" and "strange" addiction is the addiction itself ie the compulsiveness. All has physical and psychological effects in different degrees. The difference with these "strange" addictions is that we find it unsettling or hard understand. But even in religion, some find some practices unsettling and hard to understand as well. The key is to find out why.
For these "strange" addictions, strange though it may be we; apart from the possibility of poisoning; there are very little difference with "normal" addictions". Both are forms of habituations. But then this is what Buddhism is trying to get rid of. Habituations!