For the last couple of years, DigitalOcean has run Hacktoberfest, which purports
to “support open source” by giving free t-shirts to people who send pull
requests to open source repositories.
In reality, Hacktoberfest is a corporate-sponsored distributed denial of service
attack against the open source maintainer community.
So far today, on a single repository, myself and fellow maintainers have closed
11 spam pull requests. Each of these generates notifications, often email, to
the 485 watchers of the repository. And each of them requires maintainer time to
visit the pull request page, evaluate its spamminess, close it, tag it as spam,
lock the thread to prevent further spam comments, and then report the spammer to
GitHub in the hopes of stopping their time-wasting rampage.