Story
      of a man who used to sit with drinkers; and who was Abu Thawr?
Question

                I was told that there was once a brother (I dont know if he was one of the companions or at which point in history he lived in) who used to sit with people who drank alcohol solely for the purpose of making sure that on their way home they did not injure themselves. Have you heard of such a thing? 
Also waht can you tell me about Abu Thaur? I have seen his name dmentioned in the Fiqh-us-sunnah and I would like to know a little bit more about him.
Praise be to Allah.What you have mentioned is a strange story, which we
      have never heard of. But what we know and are certain of is that sitting
      with people who are drinking alcohol is haraam, because Allaah has
      forbidden the Muslims to sit in gatherings where evil things are
      happening. Allaah says (interpretation of the meaning):
 “And
      when you (Muhammad) see those who engage in a false conversation about Our
      Verses (of the Qur’aan) by mocking at them, stay away from them till
      they turn to another topic. And if Shaytaan (Satan) causes you to forget,
      then after the remembrance sit not you in the company of those people who
      are the Zaalimoon (polytheists and wrongdoers).
[al-An’aam 6:68]
 “And
      it has already been revealed to you in the Book (this Qur’aan) that when
      you hear the Verses of Allaah being denied and mocked at, then sit not
      with them, until they engage in a talk other than that; (but if you stayed
      with them) certainly in that case you would be like them. Surely, Allaah
      will collect the hypocrites and disbelievers all together in Hell.”
      [al-Nisaa’ 4:140]
 Some
      people who had been drinking wine were brought to ‘Umar ibn ‘Abd
      al-‘Azeez (may Allaah have mercy on him) and he commanded that they
      should be flogged. One of them offered the excuse that he had not actually
      been drinking, but ‘Umar commanded that he should be flogged along with
      the others, and he recited this aayah to him. And Allaah knows best.
 Concerning
      Abu Thawr, this is a brief glance at his biography:
 His name
      was Ibraaheem ibn Khaalid. His kunyas (agnomen, nicknames) were Abu
      ‘Abd-Allaah and Abu Thawr, and he is best known by the latter.
 He was
      born in Haroor in 170 AH. He was one of the fuqahaa’ of Iraq, and one of
      the scholars of hadeeth. Imaam Ahmad praised him by saying, “I know that
      this man has been following the Sunnah – i.e., the correct belief –
      for fifty years.”
 He lived
      for seventy years or more, and died in 240 AH.