Don't hate sinner but his sin

عَنْ أَبِي هُرَيْرَةَ ـ رضى الله عنه ـ قَالَ سَمِعْتُ النَّبِيَّ صلى الله عليه وسلم يَقُولُ ‏ “‏ إِذَا زَنَتْ أَمَةُ أَحَدِكُمْ، فَتَبَيَّنَ زِنَاهَا فَلْيَجْلِدْهَا الْحَدَّ، وَلاَ يُثَرِّبْ عَلَيْهَا، ثُمَّ إِنْ زَنَتْ فَلْيَجْلِدْهَا الْحَدَّ وَلاَ يُثَرِّبْ، ثُمَّ إِنْ زَنَتِ الثَّالِثَةَ فَتَبَيَّنَ زِنَاهَا فَلْيَبِعْهَا وَلَوْ بِحَبْلٍ مِنْ شَعَرٍ ‏”

‏‏Hazrat Abu Hurairah
رضي الله عنه says thatI heard the Prophetصلى الله عليه وسلمsaying, “If a slave-girl of yours commits illegal sexual intercourse and her illegal sexual intercourse is proved, she should be lashed, and after that nobody should blame her, and if she commits illegal sexual intercourse the second time, she should be lashed and nobody should blame her after that, and if she does the offense for the third time and her illegal sexual intercourse is proved, she should be sold even for a hair rope.[1]

It is clear from the above, we distinguish between a sin and a sinner. A sinner will suffer the consequences of his/her sin. However that does not give us the right to humiliate a sinner more than the specified punishment. In doing so, one will be assisting Shaitan.

Consider the following Hadith,
‏ عَنْ أَبِي هُرَيْرَةَ، أَنَّ رَسُولَ اللَّهِ صلى الله عليه وسلم أُتِيَ بِرَجُلٍ قَدْ شَرِبَ فَقَالَ ‏”‏ اضْرِبُوهُ ‏”‏ ‏.‏ قَالَ أَبُو هُرَيْرَةَ فَمِنَّا الضَّارِبُ بِيَدِهِ وَالضَّارِبُ بِنَعْلِهِ وَالضَّارِبُ بِثَوْبِهِ فَلَمَّا انْصَرَفَ قَالَ بَعْضُ الْقَوْمِ أَخْزَاكَ اللَّهُ ‏.‏ فَقَالَ رَسُولُ اللَّهِ صلى الله عليه وسلم ‏”‏ لاَ تَقُولُوا هَكَذَا لاَ تُعِينُوا عَلَيْهِ الشَّيْطَانَ ‏”
Hazrat Abu Hurairahرضي الله عنه narrates thatwhen a man who had drunk wine was brought to the Messenger of Allahصلى الله عليه وسلم. Rasulullahصلى الله عليه وسلمsaid: Beat him. Hazrat Abu Hurairahرضي الله عنه said, Some struck him with their hands, some with their garment. When he turned his face, some people said: Allah put you shame! The Messenger of Allahصلى الله عليه وسلمsaid: Do not say like that and help the devil to get power over him.[2]

However, it is important to also differentiate between not humiliating a sinner and using it as a mantra in a specific context, for example, in defence of associating oneself with a sinner to the extent that one suffers the evil effects of the sin. It is incorrect to use the statement hate the sin, not the sinner as a mantra in such a context or in similar contexts.[3]
While it is prohibited to humiliate a sinner more than the stipulated amount, it is equally important to protect oneself from the evil effects of a sinful person and his company.
http://islamqa.org/hanafi/askimam/102680