Shaikh Saleem Al Hilali said in his book: Innovations and its evil effect on the Ummah:
And a person may say: How do we know the people of innovation in order to stay away from them and warn against them, especially when many of them in this time hide under the Da’wah of Ahlus Sunnah Wal Jama’ah?
And the answer has some angles:
1) The people of innovation are known by the clarification of the people of knolwedge, and warning against their books and telling the people to flee from their sittings. And there remains- All praise is due to Allah- those who do so in every time. Hence stay with the Ulama and you will be successful.
2) A man is known by whom he enters and from where he leaves. And for this reason it is not possible for an innovator to hide his condition. It is a neccesity that he shows what gives evidence of this.
Imam Al Auza’ee said: “Whomsoever hides his innovation from us he cannot hide his friends from us.” And Mu’aadh Ibn Mu’aadh said: “Even if a man hides his opinions this is not hidden in his child, his friend or who he sits with.”
Therefore if the people one sits with are the partisans, and his scholars are the Islamic Thinkers and Activists and those whom he loves are those who have spoken ill of the scholars… is it sensible to say that he is a Sunni Salafi?