UPDATE May 3: We have re-enabled “deep” links to observations for non-logged in users. This means that URLs like https://mushroomobserver.org/obs/499785 now work for non-logged in users. This means that such URLs will work better when shared with the general public. However, these pages now have a minimal number of links when viewed by a non-logged in user. This reduces the ability of web crawlers to impact the site. Note that older links to observations like https://mushroomobserver.org/499785 or https://mushroomobserver.org/observations/499785 still require a login. This is because such URLs are apparently stored in some of the web crawlers and they continue to beat on MO with them. However, the new links (with /obs/) should now be used throughout the site.

BACKSTORY: As of April 2025 we decided to temporarily restrict access to essentially all MO content to users who have verified accounts. We have been heavily targeted by increasingly sophisticated web crawlers using many different IP addresses. Even after implementing a variety of preventative measures, this type of traffic accounts for over 95% of the traffic to our site. Also it is being done in a very crude way that denies access to users with verified accounts. Fighting this battle is a signifiant drain on our development resources and this seems like a reasonable compromise at least in the short term.

We are committed to keeping all data contributed to Mushroom Observer freely and openly available. To that end we are working on enabling “deep links” for non-logged in users. This would allow anyone to share links to specific observations or names. These would work normally for logged in users, but for users that are not logged in links to other observations or indexes would not be shown. In theory this should prevent web crawlers from discovering our content.

Note that we continue to make bundles of images and database dumps available without any login requirements from the login page. See MO Images for Machine Learning and MO Data.

If there are other important cases that you would like to discuss or you are able to help us address this issue in a better way, please let us know.