Going to Court to force an ISP to disclose the identity raises many issues including First Amendment issues. For example,
On June 13, 2007, the New Jersey Township of Manalapan filed a malpractice suit against its former attorney Stuart Moskovitz, alleging misconduct regarding the Township’s purchase of polluted land in 2005. The decision to file suit was met by a lively debate in the regional press and among localbloggers. One blogger who was particularly critical of the Township, of this and other decisions, was Blogspot blogger “datruthsquad”
(http://www.eff.org/cases/manalapan-v-moskovitz).
Long story short the Township lost, a copy of EFF’s motion squash is available here motiontoquashmpa-signed; and the Court order squashing the subpoena is available here order-122107. However, there may exist an alternative method for “unmasking” anonymous bloggers, cyber-stalkers, etc. using public information. Everyone has a unique writeprint (basically a written fingerprint that can be used to identify him or her). This technique s has traditionally been used to identify the true author of a text (e.g. a book) where authorship is disputed or unknown. Forensics linguistics has been used to provide evidence in trademark disputes cases, identifying the author of anonymous texts (such as threat or harassment letters), and identifying cases of plagiarism. The identification process relies on the analysis of an individual’s particular patterns of language use (vocabulary, collocations, pronunciation, spelling, grammar, etc.). The term “idiolect” is defined as the speech patterns of a specific person (a dialect, unique in pronunciation, grammar, and vocabulary to a single person). Stylistic features can be used to create a fingerprint of an individual’s writing style (a linguistic fingerprint is called a “writeprint”). A writeprint is composed of features that represent an author’s writing style, which are consistent across all of an individual’s writings. For a gentle introduction, see Digital fingerprints: tiny behavioral differences can reveal your identity, by Julie Rehmeyer in the January 13, 2007 issue of Science News (Westlaw cite 2007 WLNR [...]