Yesterday on MO I saw this question and gave this answer by posting a link I found by googling (more precisely, I used DuckDuckGo). The sought for paper is from a series of preprints issued by the University of Groningen (Rijksuniversiteit Groningen), therefore I thought it was something not under a paywall, wrote a simple disclaimer and posted it.
Nevertheless, I noted that the link is offered by the Anna's Archive which seems a meta search engine which give results from Sci-Hub, Library Genesis and other sites which, in some known cases, are able to circumvent paywalls. Thus here's the question: even if the said paper is freely distributable (as possibly may be many items found by using the same tool), should I delete my answer since it gives a link to a web site with potentially paywall-break capacities?
Note. I search here on meta for questions on the or analogous same topic, but I just found the following four, which are only loosely related
- Does MathOverflow help people get past paywalls?
- Are Links to Articles Behind a Paywall Acceptable Answers?
- edits with links to material under restricted access
- Are Links to Articles Behind a Paywall Acceptable Answers?
Edit. Thanks to a suggestion by Martin Sleziak, I got aware of another relevant Q&A, precisely the following one: