Third-party IPTV sits in a legal grey zone that varies by country, by provider, and even by the specific channels you watch. Here is the real picture.
Short version: IPTV technology is legal everywhere. IPTV services are legal when the operator licenses the content it distributes. Most of the ultra-cheap (<$10/month) services you find on this site do not have broadcast licenses for the content they aggregate, which makes the service itself infringing — though the legal consequences for individual subscribers vary wildly.
Copyright law in most of the EU and Commonwealth (UK, Canada, Australia) distinguishes three actors: (1) the person who uploads or distributes infringing content, (2) the person who resells access, and (3) the end subscriber. Enforcement regimes target (1) and (2) heavily; (3) variably.
We flag every provider in our directory with a "licensing unverified ⚠" marker because we cannot independently verify broadcaster licensing for most of them. Some may be fully licensed in certain territories; some clearly are not. We do not advise on legality — we report on reliability, price, and feature-set. Legality is your decision to evaluate.