Gideon Lewis-Kraus in Wired:
Oh hai. A cat wearing a short tie plays music on a cat-shaped keyboard (“Pancake Meowsic Video“, 188,083 views). A woman performs Sun salutations with a cat on her back (“Cat Loves Yoga“, 1,584 views). A man slaps two cats on an ironing board to the beat of “Atmosphere” (“Cat Slap Joy Division“, 359,461 views; watch this one). Kittens try to keep up with an accelerating treadmill (“Treadmill Kittens“, 3.4 million views). A fat cat walks on an underwater treadmill (“Fat Cat Walking on Underwater Treadmill“, 136,922 views). Two cats cuff at a treadmill in perplexed inquisition (“Cats Try to Understand Treadmill“, 1.9 million views). Search YouTube for “cat treadmill” and see how many results there are. Or, actually, don't.
Writing that paragraph took more than an hour. To continue the catalogue for an entire page would've taken weeks. But if one has set out to say something definitive about the relationship between cats and the internet, it's important not to allow oneself to be delayed indefinitely by internet cats.
The obvious place to begin an inquiry into the internet cat is with Maru, the most famous feline on the internet. Maru's shtick, in brief: Maru gets into a box (“大きな箱とねこ“,8.1 million views). Maru gets into a box (“箱とねこ8. A box and Maru 8“, 3.2 million views). Maru gets into some boxes (“いろいろな小さ過ぎる箱とねこ. Many too small boxes and Maru“, 8.1 million views). Maru tries to get into a box (“入れない箱とねこ. The box which Maru can't enter“, 2.3 million views).
More here.