Question: Is Zen actually safe?

From „Staggering Along With God“ pg. 33.
Question: Is Zen actually safe?
Answer: Basically, yes. Some meditational practices get quicker results, but are unsafe – like Kundalini, which may cause mental illness. However, nothing is completely safe. For instance, it isn’t completely safe to go to church because you might fall in love with a married person, or be manipulated by the leaders.
Anyhow, when I visited these monasteries as a Zen monk, the monks would sasy, „Come in brother, and be with us!“ I was poor, and they were poor, and we had a lot in common. We were both interested in meditation. Some of the Catholic monks recommended Christianity to me, and I became interested in the Trappist lifestyle. I asked an abbot, „Can I become a Trappist without becoming Catholic?“ He said no, and I thought, „That’s too bad.“ I’ve never wanted to be Catholic. But I was really interested in being a Trappist. It was so similar to the Zen lifestyle – simple and regular. It was a real community, so it was attractive to me. Ellis H. Potter
http://www.martinweaver.net/Ellis/index.htm