It is crazy that we can't deport people who are believed to be terrorists and who are not British citizens. The justification is that the country to which we would deport them (their own country) would abuse.
Supporters of this act claim that rights are indivisible and that we cannot pick choose when to apply rights or to whom they apply. However the principle of doing exactly this is enshrined within the ECHR itself in respect of rights to personal freedom and imprisonment for offences. so it is clear that the principle is accepted – the argument that you can't pick and choose therefore is defeated by the ECHR itself.
Why does this idea matter?
While the rights enshrined in the ECHR are laudable, I don't see why the British public should support the rights of people who seek to destroy the very system that is protecting them.