بسم الله والحمد لله وصلى الله على سيدنا محمد رسول الله وعلى ءاله وصحبه وسلم

Bismillah, praise be to Allah the of creator everything, the one who has no beginning or ending, and Whom does not resemble his creations and does not need any of his creations, we ask Allah to raise the rank of Prophet Muhammad more and to honor him and his Al and companions. And to unite our ummah ameen.

Wahhabis are a sect that emerged 250 years ago that follows a deviant man who emerged from a place called Najd, the place where the Prophet said "the tribulations and sedition will occur from there". They oppose the majority of Muslims and declare whomever opposes them as blasphemers and thus promote chaos and killing amongst the nations. 

The mufti of Makkah Ahmad bin Zaini dahlan already authored a book called "The Fitnah of Wahhabis" and he exposed some of what he saw from the wahhabi extreme and terrorist acts besides their radical beliiefs and misguidance in aqeedah. Read the book "The Fitnah of Wahhabis"

مفتي الشافعية في مكة الشيخ أحمد بن زيني دحلان، كشف في كتابه "فتنة الوهابية" عن بعض ارهاب وتطرف الوهابية المجسمة واستحلال دماء المسلمين وقتلهم وسرقهم ونهبهم باسم الدين بعد ذكر بعض عقائدهم الفاسدة التكفيرية المنحرفة عن الكتاب والسنة والسلف الصالح.  اقرأ كتاب: فتنة الوهابية

If they forbid (claiming to be bad bidaa):

Mawlid celebrating the Prophets birth
Tabarruk by the Prophet
Tawassul using the Prophet as wasilah
Ziara for Muslim graves
Tilawa for dead Muslims
Tasbeeh Zikr with masbaha beads
Madih praising the Prophet

Then know they are Wahhabis or brainwashed by them.

How could all that be forbidden and we know all Muslims practice these acts as asserted from Quran and Alsunna?

Our Prophet (Peace be upon him) said: "Follow Jama^ah and Be Warned from factions".

Let one follow the Jama^ah (Majoirty) of the Muslims by adhering to what the scholars of the four schools have deduced from al-Qur'an and Alsunna. Learn and follow the Islamic concepts taken from our Holy Book, al-Quran, and from the sayings of our beloved Prophet Muhammad Sallallahu ^Alayhi wa Sallam, and the doings of his honorable companions and the unanimous agreement of the Muslims, moderately and away from extremism.

For more details and refernces for their deviations and refuations on it, see:

Sunnis, not Wahhabis!

http://alsunna.org/Proofs-that-Wahhabis-oppose-the-way-of-True-Salaf.html

http://alsunna.org/Quoting-blasphemous-beliefs-of-Wahhabis-about-Allah-God.html
http://alsunna.org/Quoting-The-Misguidance-of-Wahhabis-in-Beliefs-Aqeedah.html
http://www.alsunna.org/forum/index.php?topic=987.0

Warning from Nasir Deen al-Albani:
http://alsunna.org/Al-Alban-s-Deviations.html