"Aman passed by Hudhaifah bin Al-Yaman and it was said to him: "This person conveys news about the people to the leaders.' So Hudaifah said: 'The Messenger of Allah said: 'The Qatat shall not enter paradise.'" (Sahih)Sufyan said: "The Qatat is the Nammam.  

سَمِعْتُ رَسُولَ اللَّهِ ﷺ يَقُولُ لاَ يَدْخُلُ الْجَنَّةَ قَتَّاتٌ قَالَ سُفْيَانُ وَالْقَتَّاتُ النَّمَّامُ وَهَذَا حَدِيثٌ حَسَنٌ صَحِيحٌ