Medical staff in the United Kingdom have been advised to use Bing after Google mistook the National Health Service for a botnet.

The NHS, which provides and administers publicly-funded healthcare in the UK, employs more than a million people. Unfortunately that adds up to so many people searching Google via the NHS network (and its associated IP addresses) that at peak points it has triggered Google’s automated defences against denial of service attacks.

This doesn’t block access but does require users to complete a CAPTCHA and prove they are human before being able to use the site. An internal email from one NHS department seen by The Register said “We are advising staff to use an alternative search engine i.e. Bing to bypass this problem.”

A spokesman for NHS Digital says the organization is now talking with Google about how to resolve the issue.

It’s not the first time the sheer size of the NHS network has caused technical problems. Last November an email mistakenly went to all 850,000 users in England with an NHS address. That might not have been so catastrophic, but around 80 people replied with messages asking to be removed from the list. Those messages also went out to everyone, triggering a chain reaction of more than 500 million messages in just over an hour.