By uploading, distributing, transmitting or otherwise using Your Content with the Service, you grant to us a perpetual, nonexclusive, transferable, royalty-free, sublicensable, and worldwide license to use, host, reproduce, modify, adapt, publish, translate, create derivative works from, distribute, perform, and display Your Content in connection with operating and providing the Service.
Literally every service where you upload user-generated content says this. Here’s tumblr’s:
When you provide Subscriber Content to Tumblr through the Services,
you grant Tumblr a non-exclusive, worldwide, royalty-free,
sublicensable, transferable right and license to use, host, store,
cache, reproduce, publish, display (publicly or otherwise), perform
(publicly or otherwise), distribute, transmit, modify, adapt (including,
without limitation, in order to conform it to the requirements of any
networks, devices, services, or media through which the Services are
available), and create derivative works of, such Subscriber Content. The
rights you grant in this license are for the limited purposes of
allowing Tumblr to operate the Services in accordance with their
functionality, improve the Services, and develop new Services. The
reference in this license to “creat[ing] derivative works” is not
intended to give Tumblr a right to make substantive editorial changes or
derivations, but does, for example, enable reblogging, which
allows Tumblr Subscribers to redistribute Subscriber Content from one
Tumblr blog to another in a manner that allows them to add their own
text or other Content before or after your Subscriber Content.
Here’s twitter’s:
By submitting, posting or displaying Content on or through the Services,
you grant us a worldwide, non-exclusive, royalty-free license (with the
right to sublicense) to use, copy, reproduce, process, adapt, modify,
publish, transmit, display and distribute such Content in any and all
media or distribution methods (now known or later developed). This
license authorizes us to make your Content available to the rest of the
world and to let others do the same.
Here’s imgur’s:
By uploading a file or other content or by making a comment, you
represent and warrant to us that (1) doing so does not violate or
infringe anyone else’s rights; and (2) you created the file or other
content you are uploading, or otherwise have sufficient intellectual
property rights to upload the material consistent with these terms. With
regard to any file or content you upload to the public portions of our
site, you grant Imgur a non-exclusive, royalty-free, perpetual,
irrevocable worldwide license (with sublicense and assignment rights) to
use, to display online and in any present or future media, to create
derivative works of, to allow downloads of, and/or distribute any such
file or content. To the extent that you delete any such file or content
from the public portions of our site, the license you grant to Imgur
pursuant to the preceding sentence will automatically terminate, but
will not be revoked with respect to any file or content Imgur has
already copied and sublicensed or designated for sublicense. Also, of
course, anything you post to a public portion of our site may be used by
the public pursuant to the following paragraph even after you delete
it.
It’s sort of a clause they have to put in there in order to do stuff like actually serving up images and generating things like thumbnails
