Fristy Frosty glass

It's been a few months since the bedroom window froze up!!  Now I know why it is called frosted glass! 

The skip parked outside our front door is being used by the neighbours builders.. but I have seen the team helping to offload waste from a van and dump it in the skip. Usually the van arrives with deliveries for the site but.. now they seem to arrive with waste from another building site!!!  I am in two minds whether to mention it to the owner who lives three miles away or not.  I have no idea if the team of builders only work for him in which case is the waste coming from his house (in which case why can he not have his own skip outside his own house) or are they bringing from another job entirely ... what would all you sensible people do.. 
a) ignore it .. it is nothing to do with me who dumps stuff in his skip
b) contact owner (who I only ever seem to comlain to about the build next door) to let him know what is happening 
c) contact owner and let him know we are not happy with rubbish from another site being dumped in the skip outside our house
d) something else to let off the steam that I can feel building