It strongly depends on a country. In most countries you are free to take and publish screenshots for a review, commentary, article etc. It's either a "fair use" or "quotation rights".
Remember, that in most law systems, takin a screenshot is just like quoting a book fragment. At least in Poland, doctrine (because there are no legal cases...) says a screenshot is a quotation just like a book quote.
In Poland you may use screencaps, quotations, examples, to make your article more attractive, to address your points better, etc etc.
Listen to me. I've got 666 rep.
Post edited December 11, 2012 by keeveek