Shaykh Saalih As-Suhaymee said, “This (boycotting of some Salafis by another group of Salafis because they did not make tabdee of a certain person – they didn’t declare a certain person to be an innovator), is from the dangerous diseases that some of the du’aat (callers to Islam) or those that claim to have knowledge fall into, i.e. being hasty in making rulings upon people and being hasty in boycotting and abandoning even if there is nothing that necessitates that. This is something that has directly contributed to splitting the ranks, especially the ranks of Ahlus Sunnah, those who are upon the manhaj of the salaf (the methodology of our predecessors).
So there is a lot of give and take between them without returning to the scholars, and it may even go as far as them declaring each other to be innovators or fasiqs (those who commit many sins openly), even though the one who is being declared this is not an innovator or a fasiq.
This happens as a result of being distant from knowledge, learning and understanding the religion of Allah, the Exalted.
Thus it is upon the Muslim to seek knowledge that enables him to distinguish between truth and falsehood and between what is good and what is bad, between Tawheed and shirk, and between the Sunnah and innovation.
We have even seen some of them, and they are a Muslim minority, fighting among themselves and they are – generally speaking – upon a sound manhaj (methodology). But personal desires, ignorance, and loving to be in front of the people, may lead some to make tabdee’ (declare one to be an innovator) as they like and to be hasty in boycotting.
However, boycotting has specific guidelines which must be taken into consideration, some of which relate to the haajir (the boycotter) and some relate to the mahjoor (the one being boycotted). Not every mistake deserves boycotting; someone may be boycotted for a minor issue due to an overwhelming belief that it will lead to a positive result, but one may not be boycotted for an even greater affair in order to avoid a fitnah and separation.
The Messenger (sal-Allaahu ‘alayhi wa sallam) boycotted the three who stayed behind [and didn’t participate in the battle of Tabook] even though their sins were nothing in comparison to the sins of the hypocrites and others who were in opposition [to the Message]. At the same time, he kept the hypocrites with him and did nothing to them so that it would not be said that Muhammad kills his followers as the Prophet (sal-Allaahu ‘alayhi wa sallam) explained to be the reason.
Therefore, the issue of boycotting without considering its pros and cons is a very dangerous issue. Maybe you boycott him and, in fact, turn him over to the enemy; maybe you boycott him and it only causes him to go further in his misguidance, or maybe you boycott him over an issue that does not deserve boycotting.
Yes, the one whose innovation and disobedience is established (verified) and it is overwhelmingly believed that boycotting will benefit him, then yes. But the opposite could be the case: you boycott him and, as a result, he reverts to committing many sins and disobedience. He may even turn to the enemies of Sunnah and you are a cause of that.
For more information about this topic read the book “The Difference between Advising and Condemning” by al-Hafidh Ibn Rajab (may Allah have mercy on him) and “An-Naseehah” (Advice to the Youth of Ahlus Sunnah) by Shaykh Ibrahim ar-Ruhaylee (may Allah preserve him).
Plus strive to avoid anything that will cause a negative reaction as is the case with many who rush to boycott for the most trivial reasons before advising and directing, or declaring his brother to be an innovator for an unwarranted reason. At least you should strive in advising and directing him, and beware of hastening to boycott.
In fact, some of those who are considered to be students of knowledge in certain countries – even though they are minorities in those lands – sometimes boycott one another. We’ve found this in some countries that we’ve visited where the Muslims are minorities.
It is upon the Muslims to return to the correct way of remedying these affairs by following the methodology of the salaf as-saalih (righteous predecessors) so that you are safe and others are safe from you.”
 Bukhari #3518 and Muslim #2583
Posted by Abdul Kareem Ibn Ozzie