Wifi access not allowing access to all sites (several incoming/outgoing IP blocked by ZoneAlarm) - hacking attempts?

Few months ago I was using my own inteet (wifi in my own studio, under windows 7) and I was able to access any website I wanted.

However, since few weeks, I moved into a shared housing and also use the shared wifi.

However for an unknown reason, OFTEN I caot access to some websites such as facebook, gmail, etc.

I've check ZoneAlarm, and there are all the time a dozen of incoming and outgoing IP address that are blocked by ZoneArlm.

Also, I would like to know what could be the reason of these issues. My PC has been ?

Thanks in advance for your help,

Jon