You must have a lot, a lot of care. Do not approach any Mayavadi. There are many Mayavadis who dress as Vaisnavas. Sri Bhaktivinoda Thakura has explained about them, saying that "there is a Kali follower here, although he has a tilaka in his nose and counts in his neck, he is a kali-celā." If he is Mayavādi, "sahaja-bhajana kache mama sange laya pare bala." So these things happen.