I’ve been on the phone 3 times with 1and1 Internet support since Saturday when we first noticed it. This is affecting two contracts and several WP installations.
1and1 support told me they are applying some security enhancements to prevent the brute force attacks against WP dashboard logins (something that has apparently been going on around the world since at least last April).
Today I was able to login to my dashboard while support was on the phone. But when I hung up, I couldn’t get in again (Error 503 Service Temporarily Unavailable). Whatever 1and1 is attempting to do, it appears to be a botch-up. There were no advance notifications, no info on when it should be (really) fixed and nothing specific about what they’re doing, except annoying their subscribers.
