One reason the LTTE got into trouble in Canada was because of its use of terror against its own supporters. To raise money, the LTTE basically holds hostage family members of expatriates. The overseas Tamils want to return to Sri Lanka to visit, but can only do so if they have paid all their "LTTE taxes" (officially, charitable contributions). If they don't make such visits, their kin are still in danger if the expatriates are not sufficiently generous to the cause. Canada, after numerous reports of illegal activity, recently declared the LTTE a terrorist organization, and made fund raising for them illegal. This came after years of complaints about LTTE terrorism, and use of strong-arm methods to get Canadian Tamils to contribute. The LTTE managed to stave off the terrorist designation for so long because the Tamil community voted heavily for the Liberal party, which, until recently, held a majority in parliament and ran the government.
The LTTE dominated Tamil community pushed all of the Liberal party's guilt buttons to great effect. This is a favorite tactic with other terrorist organizations. Islamic terrorists often get away, literally, with murder, by claiming they are victims of Western imperialism and that their terrorism is a legitimate response. Many Western politicians and special interest groups go along with this, to the great benefit of terrorist fund raising among expatriate populations. While the Tamil fund raising racket is one of the best organized, those that support Islamic terrorism also do very well. For decades, the Irish Republican Army (IRA) terrorists depended heavily on money raised among Irish-Americans in the United States.
The war on terror investigations have made it much more clear that this type of fund raising is extensive, and a critical factor for keeping terrorist organizations active. Take away the money, and you still have angry people, including many willing to kill for the cause, and risk their lives doing it. But without the money, you are left mainly with smoke, not fire. The Soviet Union was well aware of this, and funded many terrorist organizations, keeping them going and causing much death, destruction and unease in the West and Middle East. When the Soviet Union disappeared, so did a lot of active terrorists.
For many years, countries in Europe and North America had been generous in their acceptance of foreigners coming (often illegally) and asking for political asylum. Many of these asylum seekers were accused of terrorist activity back home, but human rights groups in the West had taken sides, and declared the terrorists as oppressed and worthy of asylum. Worse, everyone looked the other way as these terrorists/asylum seekers set up shop, raised money, and planned terrorist operations. Usually these attacks were to be carried out back in the old country, but eventually they were carried out against their host countries. Even the human rights activists (many of them, anyway) recoiled at this, and the bans began to appear.
Canada now fears that LTTE might launch attacks against Canadian targets. There are still LTTE terrorists living in Canada, and going after them has to deal with public attacks from human rights groups. Terrorists have rights, too, and they should be protected.
Since many more countries have declared the Sri Lankan Tamil Tiger (LTTE) organization terrorists, they have been investigating local LTTE activity more intensively. As in earlier experiences with groups like Hamas, the IRA and Hizbollah, it was discovered that the fund raising front organizations hid terrorists, and often plans for local terrorist activity. Canada recently announced that, on closer examination, it had found that the LTTE was not only ready for running terrorism operations, but was already doing so. And more might be on the way.