Could be the site was configured to use IE6 NTLM authentication, which other browsers don’t support. Could be to maintain an audit trail of who accessed what, e

Could be the site was configured to use IE6 NTLM authentication, which other browsers don’t support. Could be to maintain an audit trail of who accessed what, eg for SOX compliance reasons. It was / is not uncommon for big corporations with an SOE / golden image with Windows vXX and IE vXX to do this. Not saying this to defend his / her dickhead behaviour, though. It’s very different (and extremely lazy) for a public web site.