While I agree that Canadians, exceptions aside, have a more negative view of China than the reality, I will say this about the riots:
Both the Uighurs and the Han who engaged in the riots were out of line.
Do I agree with executing those who may have committed murder? Exceptions aside, yes.
I would like to emphasize this, however: The Uighurs do have some very legitimate grievances. I have known Uighurs in China, and have visited Urumqi, the very site of the riots today, and spoken to many Uighurs, and can say that there is essentially a subtle policy of cultural genocide against them by the government. It is subtle though, and the government is very good at PR and psychological manipulaiton. To take an example:
In Xinjiang, both Mandarin and Uighur are co-official languages. Fair enough. But they are not totally equal. Parent can choose to send their children to either Uighur-medum or Mandarin-medium schools up to the end of middle or high school (I can't remember which), after which they must transfer to Mandarin-medium instruction in higher education.
I'd visited Urumqi in 2001, the same year that a government law banning the University of Xinjiang from offering courses in Uighur was to take effect. Sure it could teach Uighur itself, but could not teach in Uighur. Obviously a Uighur parent looking forward to his child learning his mother tongue and getting a higher education finds himself with a tough decision to make. Of course the government will rub in the fact that they do have a 'choice', ignoring the consequences of the choice. It's all PR in the end, with the government giving insignificant rights to the now-minority language community, and then rubs it in for PR effect, when in reality these 'rights' are meaningless if the pupil intends to move his way up in society.
Of course the Uighurs aren't stupid and can see right through this PR, and are fuming angry about it.
Evenin 2001 I could feel the tension in the air. The city was above in the day, but as soon as the sun went down, nearly all went home. The city was clearly though unofficially deliniated, with the Uighurs, Hui, Kazakhs, and others (though mostly Uighurs) living in their minority enclave of town, and the Han living in theirs. Needless to say the Han secotr was the more developed one.
Ethnic prejudice and hatred was ripe too. I'd been told off for daring to speak Han to a Uighur on one occasion, and having some Han asking if I was 'one of them' (referring to Uighurs) before becoming friendly with me, and when I'd say I'm not Uighur, they'd spew out their prejudices such as that Uighurs are thieves, trouble-makers, traitors, etc.
The local Han make no effort whatsoever, a few exceptions aside, to learn the local language and culture, or even to acknowledge it and give it its due respect, while the Uighurs feel themselves assimilated in Han schools.
I remember reading one article in which a Uighur was saying that Uighur teachers would often teach their own culture in school and ignore the rules (though usually the headmaster would be a Han, a member of the CPC, and often didn't know Uighur himself). Soon afterwards, a new 'teacher' would appear, a Han, and the Uighur teachers would immediately avoid that person out of suspicions that it's a spy.
The recent riots are not some surprise event born out of thin air, but come rather from a long history of ethnic injustices imposed on the Uighurs by the Han majority.