This is a thorny issue的意思|示意

Although this sounds like a thorny problem, this particular issue by itself is probably not the cause of the data corruption problems that people have been experiencing.

尽管听上去这是个棘手的问题，但这个特定问题本身可能不是人们所遇到的数据毁坏问题的原因。

It is brought out a common attention is how to effectively protect environment all over the world and the environmental issue has become one of the most concern and thorny issues in this century.

环境质量及环境保护日益受到世界各国的普遍重视，环境问题已成为本世纪最为关注和最为棘手的问题之一。