Apostrophes - the greengrocer's

Islamist group's such as the Muslim Brotherhood... argue that... only a parliament chosen by free election can set the terms for a constitution. (Globe and Mail, 29/07/11)

This particular error used to be known as the greengrocer's apostrophe, because of the signs in the shop window saying "Apple's", "Orange's". These of course are plurals, not possessives, and don't require an apostrophe at all.

As Pope said, "A little learning is a dangerous thing." Some people learned at school to put an apostrophe before the "s" and extended the rule to every "s" they wrote. 

They would also, incorrectly, put an apostrophe before the "s" in a third person singular verb, as in "Rock and roll rule's!"

The Globe reporter, or his proof reader, should have said:

Islamist groups such as the Muslim Brotherhood... argue that... only a parliament chosen by free election can set the terms for a constitution.