I listened to most of a 60 minute presentation of this research by Pew. It was informative and ground-breaking. At the same time, Pew expects their report to be skewed by misleading headlines. So, here are some of the findings, in balance:
1. While many chaplains (most of whom were white, older, and Protestant Christian) did see some amount of "religious extremism," only 4% saw any kind of security threat at all. One example cited of extremism is the belief that all those not a member of my faith tradition will go to hell. Extreme? Perhaps. That's in the eye of the beholder. However, that idea is not going to result in some one blowing up bombs or starting riots.
2. While there is a lot of "switching" in prisons, it is often temporary, and also often done for "privileges." For example, Jews might be seen as getting better meals, and extra matzo crackers and juice for their sabbath. Switching may also be done more for social reasons than for spiritual crises reasons.
3. The report correctly points out that most chaplains are very satisfied with their labor.
For those truly interested, I suggest scanning the actual report. While it's about 100 pages, reading the beginning and the end, and a few paragraphs after interesting headings will give you a better picture of the research.
Religion in Prisons: A 50-State Survey of Prison Chaplains - Pew Forum on Religion & Public Life