Contrary to what you see on Hindi movies like 'Padosan', or what White-skinned tourists' testimonials are, Tamils as a collective are neither meek nor friendly. Tamils are possessive, feudal, clannish and arrogant, though not as much as another South Indian group, which I am afraid to name here. They also have a well-developed martial tradition, which waned during the British occupation. Still, Tamils and other South Indian collectives were preferred to be shipped over to other places for their manual labour skills.
This might be true to some extent, usually during peacetime. But it is an altogether different story otherwise. A few centuries ago, they were seen as one of the most brutal and ruthless tribes to have ever encountered. The Pallavas, and later the Cholas, often invaded their neighbours at the drop of a hat. The Cholas went as far as building a belligerent Navy, the first in India. The spread of Hinduism in South East Asian countries is mainly due to the conquest of the Chola Navy.
It is said that 'the ruthless Chola conquest was apparently no different from the conduct of Mahmud of Ghazni at Somnath. The Kulavamsa says that the capital Anuradhapura, which sported many Buddhist viharas, was 'utterly destroyed in every way by the Chola army.' Not only were the viharas decimated, but the holy stupas in them were torn apart in search of treasure. Historians say that the imperial Cholas have left their mark not only on the coronation rituals of the Royal house of Thailand but that the fear of their military power has been inscribed in the etymology of the word Tamin in the Thai language. (the word 'Tamin' in Thai denotes both violence and the Tamil ethnic group). Modern day Tamils? LTTE, Veerappan, 'Auto' Shankar, the gangsters and the policemen of Tamil Nadu But, I am digressing.
Unless you belong to the ingroup, your life will not be easy. In short, Tamils are not the meek and sweet guys as seen by others. The modern times have taken some sting out of them, and the law of the land has blunted the barbs to some extent.
Why am I writing this? I have to encounter them and deal with them on a regular basis, in the form of bus drivers and conductors, auto drivers, shopkeepers, et al. If you are considered an 'outsider', expect to be ridiculed, threatened, and god forbid, expect further. Since autodrivers and friends are the only contact with foreigners and other state guys when they come to Chennai, they see the friendly friend and his family, and the obnoxious autodriver, and conclude this is limited to the autodrivers.
I realised this whole ingroup-outgroup thing even among my close friends this summer. Usually Tamil friends send some insulting text messages between themselves. For the summer, I had a different mobile number. When I sent one such message to a family friend back home (the message was a mosquito bite compared to the messages that are usually sent), I got a very rude set of words in reply , words that would make a sailor blush. I realised, I had not given my new number to this guy . I identified myself and I was back in the game . This also works in government offices and other places. You have a friend there, the bribes are reduced, and the works speed up.
More about those bloody autodrivers later.