Yet if you, as a reviewer, are confident in your opinion, then why should you hide your name?
Could it be that anonymous peer review (APR) is grounded in fear of looking foolish in case you (the reviewer) turn to be wrong? But to face the risk of being wrong is an inherent part of the vow we all implicitly take in choosing an academic career in the first place.
I see no ethical base for peer-review anonymity. Most newspapers (including The Scientist) will not publish anonymous letters. In most other creative areas (music, poetry, visual and performing arts, architecture, and so forth), criticism--even the most harsh--is invariably open. Only science, by some strange twist (perhaps a hidden inferiority complex) has developed APR. To my knowledge, the legality of APR was never clearly established. If contested, it will likely run into conflict-of-interest trouble. (Peer reviewers and the authors are competitors ...