Yes. This error is most likely coming from your ISP - and you would want to contact them to rectify it. (Alternatively, if you are an employee at a company or similar, it is possible your network administrator has put this limit in place).
Your connection is being temporarily (and automatically) blocked because of what the system deems is excess use - although how exactly it is determining this is not clear. If you are running any P2P applications (ie file sharing), you should stop them, as one [of many] possibilities is they provider is trying to limit your usage because of a large number of simultaneous connections - this is typical filesharing behaviour.