Or just consider how often we hear that Roman Catholics are "Protestant".
I think I've heard that one a few times...
"'All Protestants are Crypto-Papists,' wrote the Russian theologian Alexis Khomiakov to an English friend in the year 1846.'... To use the concise language of algebra, all the West knows but one datum a; whether it be preceded by the positive sign +, as with the Romanists, or with the negative -, as with the Protestants, the a remains the same. Now a passage to Orthodoxy seems indeed like an apostasy from the past, from its science, creed, and life. It is rushing into a new and unknown world.' [From a letter printed in W.J. Birkbeck, Russia and the English Church,
"Khomiakov, when he spoke of the datum a, had in mind the fact that western Christians, whether Free Churchmen, Anglicans, or Roman Catholics, have a common background in the past. All alike (although they may not always care to admit it) have been profoundly influenced by the same events: by the Papal centralization and the Scholasticism of the Middle Ages, by the Renaissance, by the Reformation and Counter-Reformation. But behind members of the Orthodox Church -Greeks, Russians, and the rest - there lies a very different background. They have known no Middle Ages (in the western sense) and have undergone no Reformations or Counter-Reformations; they have only been affected in an oblique way by the cultural and religious upheaval which transformed western Europe in the sixteenth and seventeenth centuries. Christians in the west, both Roman and Reformed, generally start by asking the same questions, although they may disagree about the answers. In Orthodoxy, however, it is not merely the answers that are different - the questions themselves are not the same as in the west.
"Orthodox see history in another perspective. Consider, for example, the Orthodox attitude towards western religious disputes. In the west it is usual to think of Roman Catholicism and Protestantism as opposite extremes; but to an Orthodox they appear as two sides of the same coin. Khomiakov calls the Pope ' the first Protestant', 'the father of German rationalism'; and by the same token he would doubtless have considered the Christian Scientist an eccentric Roman Catholic. 'How are we to arrest the pernicious effects of Protestantism?' he was asked by a High Church Anglican when visiting Oxford in 1847; to which he replied:' Shake off your Roman Catholicism.' In the eyes of the Russian theologian, the two things went hand in hand; both alike share the same assumptions, for Protestantism was hatched from the egg which Rome had laid.
'A new and unknown world': Khomiakov was right to speak of Orthodoxy in this way. Orthodoxy is not just a kind of Roman Catholicism without the Pope, but something quite distinct from any religious system in the west."
-Bishop Kallistos Ware (then Timothy Ware, PhD, Oxford), The Orthodox Church
(NY, Penguin), from the Introduction. http://www.amazon.com/The-Orthodox-Church-New-Edition/dp/0140146563
*Ducks head to avoid flying shoe*