[bergerjac]

Blogs have done this for years via a "pingback".

There could be some confusion between "taking" and "sharing"...

He never claims to own the photo.

He credits the original content creator. Additionally, content creators love when their content is shared, because "Someone with an audience of 20k people just shared one of my photos?! #exposure!"

[JeremyBanks]

"#exposure!" is the common refrain of the thieves, not the artists.

[mtnGoat]

very true!

[WilliamEdward]

Wow. I cannot believe people still think this isn't copyright infringement. Crediting the work of others saves you from plagiarism, it does NOT save you from copyright. Instagram does not have a "pingback" feature. It's literally a copy pasted image, with a link in the description.

[sct202]

A lot of regrammers try to hide the original poster by cutting off watermarks, and jamming the attribution far below the (more) cut off if they even bother with attribution at all.