Sheikh Salman al-Oadah
Wearing long robes that drag below the ankles is just like any other sin. The one doing so comes under the general rule of being enjoined to what is right and forbidden from what is wrong (al-amr bil-ma`rûf wa al-nahy `an al-munkar).
He should be asked to avoid such clothes, but with wisdom and beautiful preaching. The one calling him should take care to avoid embarrassing him with comments and sharp criticism. There is a lot of good in people, even if they exhibit some violations. We do not have to accuse them of being bad.
Anybody forbidding others from bad acts should do so amicably. If a person were to stand somewhere and stop every passerby who was doing something wrong – someone is dragging his rone below his ankles, someone is dressed immodestly, and someone else is smoking, etc. – and argue with them all, trying to convince them to change, he would be helpless, bring harm to himself and end up hurting others too. He will not be able to achieve his objectives.
Enjoining what is right and forbidding what is wrong is contingent upon whether or not it can bring about positive effects. It should be conducted properly and in a way that the one being advised is likely to accept it. Otherwise, the results could be an increase of the wrongdoing that one is trying to prevent.
All of this comes under the banner of wisdom. Allah says: “And he to whom wisdom is granted has indeed been given abundant good, but none will take heed except people of understanding.”
Source: Islam Today