Every year, on the 2nd of January, “El día de la Toma de Granada ” is celebrated in Granada in Spain. On that day in 1492, Muhammad XII of Granada  (King Boabdil) surrendered the Emirate of Granada . The Umayyad Caliphate conquered the Iberian Peninsula  eight centuries earlier, and the fall of Granada on that day put an end to the Islamic control of that part of the world, or what is known in as Al-Andalus  in the Arab world.
This year, on the other side of The Mediterranean Sea , some Arabs decided to tweet in remembrance of the fall of Al-Andalus.
@taherofficial : We remember the 521st Anniversary of the fall of Al #Andalus.
Many netizens seized the opportunity to tweet about the Islamic and Arabic civilization:
@adnan_hws : Remembering #Andalus is more than crying for the loss of a kingdom, it's to learn from our mistakes to rebuild such a glorious civilisation
@morabeteen : الأندلس ليست بمكان ولا زمان, بل هي تجربة حضارية إنسانية لا مثيل لها استمرت تنير ظلمات العالم زهاء الثمانية قرون من الزمان..
@morabeteen : Al Andalus is not just a place or chapter in history, it is an unmatched civilization in the history of mankind that kept on illuminating the world for about eight centuries.
Others claimed more examples for the effect of such civilization:
@Nouh1919 : In Portuguese there are more than 3000 Arabic words as there are over a 1000 Arabic words in medicine and chemistry in English! #andalus
@mdamra : While London is sinking in mud, Córdoba recorded the 1st dustbin in history, there were collection vehicles and street cleaning!
However, a bigger debate started on Twitter later on. Some users believed that this day marks the loss of a part of the Islamic world.
@HmdSaud : Do you think dear Spanish we forget it
@AliElKhateeb : on January 2, 1492, Emir Muhammad surrendered the Emirate of Granada (#Andalus ♥), we won't forget any land taken from Muslims by force.
@NadaMadridista : On this day above all days we recall those who were murdered and tortured by the Spanish Inquisition 5 centuries ago. #Moorish #Andalus
While others replied by saying that it was basically an occupation.
@samaralii : اسمها عودة الاندلس لأهلها الإسبان بعد احتلال عربي، زي كده سينا رجعت كاملة لينا، بلاش تكيلوا بميكيالين
@samaralii : It is called the return of Al-Andalus to the Spanish people after it has been occupied by the Arabs. It is the same as we [Egyptians] reacquired Sinai  after it has been occupied. Stop having double standards.
@MoudBarthez : زعلان ان الأندلس راحت منك ؟ كان نفسك تفضل محتلها طول العمر ؟ علي كدا شباب بريطانيا لازم يتظاهر عشان يرجعوا يحتلوا مصر تأني
@MoudBarthez : Are you sad because you lost Al-Andalus? You wish you had occupied it forever? If so, then the British people should demonstrate to re-occupy Egypt again.
Yet, others insisted that it was not an occupation:
@alaa : حكم المسلمون الأندلس سبعة قرون لا يمكن ان يوصف بالاحتلال و لا معنى لتقييم حكمهم بمعايير اليوم اصلا.
@alaa : The Arab ruling of Al-Andalus for seven centuries can never be described as occupation. And no way to evaluate it with today's standards.
@SherifKhairy : الناس اللي بتتكلم عن إن حضارة المسلمين في #الأندلس كانت احتلال زي احتلال الإنجليز مثلا، بالتأكيد مقرأوش كلمة عن ما حدث وقت دخولها وبعده
@SherifKhairy : Those who call the Muslim civilization in Al-Andalus occupation, and compare it to the English occupation of Egypt, for sure never read a word about that phase of history.
One netizen created a mobile application  to mark the occasion, while two others decided to make fun of the whole debate. The first was worried [Ar]  that FC Barcelona might become as bad as the the Egyptian football teams if Arabs decided to occupy Al-Andalus again. While the other, after looking at the status of the Arab world today, decided that “we did them the biggest favour ever ” by leaving them alone.
Finally, this debate didn't stop some Egyptians from arranging a demonstration  carrying banners that read in Spanish, “No hemos olvidado” [We have not forgotten] and “Volvera por supuesto” [We will be back for sure”].