Sounds normal to me, SIM cards contain config data for connecting to the network, setting up APN's, passwords etc. Makes sense for the povider to send you to their website to create an account etc.
They installed Facebook too.
The sim is with a sub company of vodafone and the sim was in the phone for a few months before it did this.
Oh, thought it happened when you installed the SIM. May have been a system update, phones come with all sorts of crap pre-installed now as they get paid for it.