Website attacks are common place and our websites are no exception, which is why we take security very seriously and keep furthering the measures we take. One method of attack is to try multiple username and password combinations in order to find the correct log in details and break into the WordPress control panel for a particular site.
Fasthosts have implemented a security process and policy to help mitigate against these types of attacks. It can however mean that to log in to your website you may have to make more than one attempt by refreshing the screen. you will know if you get a 503 error messages. Unfortunately they are unable to tell who is legit and who are not.
We apologize for this disruption in our service, it is out of our control. If you are affected please let us know so we can monitor the situation.