According to Simon Denyer, "Libyan rebels seize western border crossing, as fighting in mountains intensifies", WaPo 4/21/2011:
Berbers have long faced suspicion and discrimination under the government of Libyan leader Moammar Gaddafi, and many towns and villages took part in the uprising against his rule in mid-February. In recent days, the government has made a renewed bid to reclaim the Nafusa Mountains, which begin around 60 miles south of Tripoli and stretch westward to the Tunisian border, from rebel rule. [...]
Gaddafi called Berbers, also known as Amazigh, a “product of colonialism” who were created by the West to divide Libya. The Berber language was not recognized or taught in schools, and it was forbidden in Libya to give children Berber names.
The policy was relaxed in 2007, but a U.S. embassy cable released by Wikileaks said this relaxation was limited, and quoted Gaddafi as telling community leaders: “You can call yourselves whatever you want inside your homes — Berbers, Children of Satan, whatever — but you are only Libyans when you leave your homes.”
An earlier discussion by Lameen Souag, "Linguistic diversity in Libya", Jabal al-Lughat 3/9/2011:
A very large majority of Libyans have Arabic as their mother tongue – in fact, Western Libya was described by the colonial anthropologist Evans-Pritchard as the most Arab place on earth outside Arabia itself. However, the country also has a noteworthy Berber-speaking minority (about 5%, if you dare to trust Ethnologue; it's not as though anyone's ever counted them in the past several decades.) Most speakers are concentrated in the northwest, where they (traditionally, for once) call themselves Imazighen: the port of Zuwara, along with many towns of the Nafusa mountains, such as Yefren and Nalut. All of that region – Arabic-speaking towns as well as Berber-speaking ones – is currently reported to be free of Qaddafi; language, thankfully, does not appear to be acting as a dividing factor there. [...]
[F]or decades, Libya has been practically terra incognita for descriptive linguistic research: even work on its Arabic dialects has been scarce, let alone on politically sensitive minority languages. When (inshallah) the Libyans establish a stable and free state, it would be well worth documenting its linguistic diversity, both for better interpreting North African history and for informing Libyan educational policy.
For those who don't already know, I should explain that before the Phoenician colonizations three thousand years ago or so, before the Greek colonies, or the Romans after them, or the Vandals in the 5th century A.D., or the Arab invasions of the 7th century A.D., or the Ottomans in the 16th century, or the French and Italian colonizations in the 19th and 20th centuries, the dominant indigenous languages of North Africa were members of the Berber family.
The term Berber is commonly used, though as often with such terms, it originates from outsiders' not-especially-respectful description. According to the OED, the term is
ultimately < Arabic Barbar, Berber, applied by the Arab geographers from ancient times to the original inhabitants of N. Africa, west and south of Egypt. According to some Arab lexicographers, of Arabic origin, < Arabic barbara ‘to talk noisily and confusedly’ (which is not derived < Greek βάρβαρος); according to others, a foreign word, African, Egyptian, or perhaps < Greek. The actual relations (if any) of the Arabic and Greek words cannot be settled; but in European languages Barbaria, Barbarie, Barbary, have from the first been treated as identical with Latin barbaria, Byzantine Greek βαρβαρία land of barbarians
Ethnologue distinguishes 25 modern Berber languages. The Berber family is a branch of Afro-Asiatic, whose sibling language families include Chadic, Cushitic, Omotic, Egyptian, and Semitic. Significant fractions of the population of some other North African countries are Berber-language speakers. Thus the Wikipedia article on Berber languages says that
In 1952, André Basset ("La langue berbère", Handbook of African Languages, Part I, Oxford) estimated that a "small majority" of Morocco's population spoke Berber. The 1960 census estimated that 34% of Moroccans spoke Berber, including bi-, tri-, and quadrilinguals. In 2000, Karl Prasse cited "more than half" in an interview conducted by Brahim Karada at Tawalt.com. According to the Ethnologue (by deduction from its Moroccan Arabic figures), the Berber-speaking population should be estimated at 35% or around 10.5 million speakers. [...]
A survey included in the official Moroccan census of 2004 and published by several Moroccan newspapers gave the following figures: 34% of people in rural regions spoke a Berber language and 21% in urban zones did, the national average would be 28.4% or 8.52 million. It is possible, however, that the survey asked for the language "used in daily life" which would result of course in figures clearly lower than those of native speakers, as the language is not recognized for official purposes and many Berbers who live in an Arabic-speaking environment cannot use it in daily life; also the use of Berber in public was frowned upon until the 1990s and might affect the result of the survey.
According to Bruce Maddy-Weitzman, "Ethno-politics and Globalisation in North Africa: The Berber Culture Movement", The Journal of North African Studies Vol. 11, No. 1, March 2006:
Contemporary processes of globalisation have stimulated and reinforced a speciﬁc Berber/Amazigh ethno-political identity. Overall, the Berberist discourse is profoundly sympathetic to Western liberal-humanist values, and strongly condemnatory of the predominant monocultural order based on Islam and Arabism. To be sure, globalisation’s homogenising effects are seen as a threat to indigenous peoples’ cultural identities, Berbers included. But, overall, modern Berber imagining is bound up with a secular, Western-modern vision of the future. Berber/Amazigh culturalists seek to accommodate larger outside forces while placing an explicit emphasis on the collective ‘self’, thus posing a challenge to the existing order in the Maghrib.
Maddy-Weitzman points to "the Moroccan Amazigh intellectual Mohammed Chaﬁk, ﬁrst head of the recently founded, ofﬁcially sanctioned Royal Institute for Amazigh Culture (IRCAM)".
‘In my part of the world,’ he declared, there is an urgent need to imbue culture with a humanism, modernism and universalism that rejects excess. This is because unitarianism and fundamentalism have demonstrated their destructive power throughout history to the extent that the threat of ethnic cleansing and religious conﬂict is still all too present.'
Chaﬁk’s universalist vision was dedicated to ‘achieving peace amongst different ethnic groups along with a real understanding between religious faiths’, beginning with the Amazigh people, whose ‘vibrant culture’ could, like all cultures, contribute something unique to the totality of human experience. Seeking to deﬂect criticism from the Islamists while placing the Amazigh movement ﬁrmly within the humanist fold, Chaﬁk emphasised that because it [the Amazigh movement] does not claim to be the depository of the sacred, it is not opposed to evolution. In its way, it is humanist because it remembers a distant past when it was well represented in the concert of Mediterranean cultures by ﬁgures such as Terence (Afer) [Carthage-born Roman playwright, c. 190– 160 BC], Juba (Juba II) [Roman client king of Mauritenia, 25– 23 B C], and Apuleius (Afulay) [second-century AD philosopher and rhetorician in Roman North Africa]. In short, Amazigh culture can enter and beneﬁt from the worlds of politics, economics, society and justice without the risk of any real prejudice to religious faith.
The 79-year-old Chaﬁk (b. 1926) was the principal author of the ‘Berber Manifesto’, an extraordinary document signed by hundreds of Moroccan Berber intellectuals. The manifesto laid out an interpretation of Moroccan history radically at odds with the standard, ofﬁcial version, and a set of concrete demands for placing Morocco’s Amazighity at the centre of the country’s collective identity. It posited the Amazigh’s traditional political cultural traditions of dialogue and consultation in opposition to the despotism imported from the early Islamic empires of the East, the Umayyads and Abassaids (but not from the Prophet Muhammad, the manifesto stressed, or his immediate successors, the four ‘Rightly Guided’ Caliphs, a period considered by believers as Islam’s most perfect moment in time).
Terence and Apuleius are less politico-religiously charged ancestors than Augustine, who was apparently also ethnically Berber.
An English translation of the Amazigh Manifesto is available here.