We took a water taxi to the venezia train station and a guy came and put our luggage in his cart. We followed him and i prepared a 10 euro tip for the 4-5 min walk. He demanded 55 euro. We ended up giving him 40 euro, but I'm angry at the whole situation.
Another family came next with one of those porters, and they also told me they were scammed out of 25 euro when he asked for more money.
We had 4 wheelie bags and we were 4 adults and we could have easily wheeled our own bags. I actually thought i was being nice by letting him make the 10 euro tip.
The hotel or taxi driver should have told us about this scam. Beware!