I have been repeatedly hitting the spam blacklist with disallowed links when running the Portable Antiquities Scheme batch upload project (this is around 400,000 files, see link below). The reason that the links are are used is that curators and reporters of finds, have been using link shortening when referring to well respected sites, such as the British Museum. These links are then used when importing to Commons, as we are using the curator's descriptions to help describe the imported photograph on Commons.
Though it is possible to trap specific links (like bitly) and reword the link to "hide" it from the spam filter, the source database is not a risk to Commons and as the curators are free to add any links they find useful to the descriptions, it is unpredictable for a batch uploader to try to work around them and "hiding" the links is not actually solving any real problem.
This proposal is that we should either white-list an upload source source site when using API upload calls, so that at the point of image upload with its associated image text, the text itself is exempt from the spam filter, or the uploading user can apply for an account temporary exemption to the spam blacklist for the duration of their upload project. The exceptions could be managed via bureaucrat approval and would pose a very low risk to Wikimedia Commons, compared to the lost value when we have failed uploads from sites like the Portable Antiquities Scheme that are unlikely to be re-done due a lack of skilled volunteers to address the blacklist 'bounces' on a case by case basis.
- PAS project page https://commons.wikimedia.org/wiki/User:F%C3%A6/Project_list/PAS
- Example bounce case with (volunteer time-expensive) manual work-around https://commons.wikimedia.org/wiki/User_talk:F%C3%A6#Blacklist_hits