The majority of Brits will soon need a BBC account in order to watch iPlayer, listen to iPlayer Radio and use some of the broadcaster's other services. The BBC has said that registration will move from optional to mandatory within the next few weeks.
The BBC says it's introducing mandatory logins to [...] but there's also a secondary motivation: Making sure you're paying your TV licence.
BBC Blog: The next stage of a more personal BBC for everyone
TV Licence: Official TV Licensing website - Home
I don't understand why such thing exists, currently it's £147 a year.