Prone to wiping their galleries/tumblrs and creating new aliases. Tagged as crookedtrees due to their wishes:

"I would prefer if all art I created after today be labeled under this name though," - crookedtrees (partial quote from Jun 30 2011 on FA)

Current accounts with content use the names cassetterecorder and variations:

• DeviantArt: https://cassetterecorder.deviantart.com/
• Fur Affinity: https://www.furaffinity.net/user/cassetterecorder/
• Pixiv: https://www.pixiv.net/en/users/3140607
• Tumblr: https://cassetterecorder.tumblr.com (marked as mature/safe mode)
• Twitter: https://twitter.com/cassettedraws
• Newgrounds: https://cassetterecorder.newgrounds.com/

Had a secondary alias named unicoitus, but that tumblr has since been wiped: https://unicoitus.tumblr.com

Used to run a grimdark/humorous pony ask tumblr called "Ask Pinkamina Diane Pie", which was wiped but attempts have been made to restore the contents: https://askpinkaminadianepie.tumblr.com

A new pony tumblr featuring Princess Luna was created which was supposed to be a more focused storyline, though it appeared to have died after a few entries and was later similarly wiped: https://illunisghosts.tumblr.com

Old accounts:

svefnn, wiped (didn't last very long)
https://svefnn.deviantart.com/
https://www.furaffinity.net/user/svefnn
https://svefnn.tumblr.com/

crookedtrees, all wiped
https://crookedtrees.deviantart.com/
https://www.furaffinity.net/user/crookedtrees/
https://allthecrookedtrees.tumblr.com/ (taken over by a scammer/advertising)
https://crkdtrs.tumblr.com/

Railgunner/SirRailgun, still has content up
https://sirrailgun.deviantart.com/
https://www.furaffinity.net/user/railgunner
https://notrailgunner.tumblr.com/ (this tumblr is now gone)

acrylicsoup, old personal blog, wiped
https://acrylicsoup.tumblr.com/

toriningendesertparty, possibly the oldest, used to be locked with a password for years but has since been either wiped or taken over by another user:
https://toriningendesertparty.tumblr.com/