Someone is using my music without permission. What Can I do?

Each channel has means to report any content infringement and claim the original rights work.

Here the links where you, as an artist, can start the claim: 

• iTunes: https://www.apple.com/legal/internet-services/itunes/itunesstorenotices/
• Spotify: https://www.spotify.com/es/legal/infringement-form/
• Deezer: https://support.deezer.com/hc/es/requests/new?ticket_form_id=360000057889 
• Amazon: https://www.amazon.com/report/infringement
• Beatport: http://forms.beatport.com/form/51386983261968
• YouTube Music: https://support.google.com/youtube/answer/2807622?hl=en
• Akazoo: https://www.akazoo.com/site/documents/contact-us
• TIDAL: https://support.tidal.com/hc/en-us/requests/new
• TikTok: https://www.tiktok.com/legal/report/Copyright

However, if you find your music in an illegal music page, then you have three ways to report this type of webs, as the legal route of the major part of the cases is difficult, and we can't know exactly who is behind that: 

1. If the website has Google advertising, you must proceed with the report in Google Adwords under the american law DMCA (Digital Millenium Copyright Act). It actives a proceed so the website has to interrupt any download or streaming of the content, in a preventive way, since the incident is solved. 
2. Same proceed in Facebook. In both cases they will interrupt immediately the activity.
3. Another option is to consult: www.whois.com, so you can discover who is the web domain owner, and disconnect him.