Passle's technology allows users to select short quotes or passages from online articles and comment on them. There are limits imposed, such as only allowing 140 words to be selected and always including an attribution link. When a user quotes from a source, they are able to give commentary, critique, or review of the quoted material. Fair use copyright in the UK permits limited quotations for the purpose of critique or review, as long as the source is acknowledged, the quote is supplemented by discussion, and the amount quoted is acceptable for review.