Witholding Knowledge For Fear Of Abuse

To withhold knowledge is a major sin.

Rasulullah SAW said:

"That person who asked about anything (in Shari'ah and conceals it), on the day of Qiyamat, a reign of fire will be placed for him."

On the other hand, to abuse knowledge is also a major sin.

Rasulullah SAW said:

'To give (Islamic) knowledge to an undeserving person is like casting pearls on the neck of a swine."

Thus the lesson learnt here is that we must be careful and selective in conveying and spreading knowledge. When things are held back (temporarily), the intention must be for fear of abuse of knowledge rather than concealing knowledge - which is a major sin.