Singer Taylor Swift has come under fire for releasing music on Spotify on the same day as her pop nemesis Katy Perry unleashed her album.
The pair have had a frosty relationship since rowing over backing dancers.
But the timing of Swift's decision has sparked a backlash, with the singer accused of being "immature" and "petty".
Swift, who pulled her songs from the streaming giant in 2014, said s he wanted to put her back catalogue of songs on Spotify to "thank" her fans.
"In celebration of 1989 selling over 10 million albums worldwide...Taylor wants to thank her fans by making her entire back catalog available to all streaming services tonight at midnight", her team announced on Twitter.
Swift had been one of the most popular artists on the service when she pulled out, after saying "it's my opinion that music should not be free".
Some people were unimpressed with Swift's timing - coming on the same day as Perry released new album Witness.
@roarsus wrote on Twitter: "I think we all can agree Taylor Swift is the most immature artist of all time."
@thranduiIien added: "Taylor Swift's the kind of person who'd go into labour at someone else's baby shower or announces her engagement during someone else's wedding."
@jasmynexv wrote: "Taylor Swift putting her music back on Spotify because Katy Perry is releasing her album tonight is the level of petty I aspire to be."
@Jazzdragon wrote: "I have no loyalty with any artists on music but after what Taylor Swift just did, I'm listening to Katy Perry's new album."
@GagaNewsShade wrote: "I always defended but today I realised, Taylor Swift is a REAL snake. She's so immature. Always try to play victim."
But @HaleyyyEvans said: "Honestly Taylor Swift coming back to Spotify is the best thing that's happened to me all year."
And @elzucks wrote: " Taylor Swift is putting all her music back on Spotify... and I couldn't be more thankful blessed".
@shelbymaine added: " Taylor Swift is putting her music back on Spotify and that's probably the best news I've gotten in a while tbh."
Perry recently admitted that the feud between the chart stars was real.
"There is a situation. Honestly, it's really like she started it and it's time for her to finish it," the Roar singer told James Corden on the Late, Late Show.
"She writes a song about me and I'm like 'OK, cool, cool, cool. That's how you wanna deal with it?' Karma.
"I'm ready for that BS to be done."