Scammers at Sacre Coeur in Paris. They block a chokepoint on the stairs up to the top of the hill and will pester you about signing some bollocks petition. I got "deaf refugee children charity". It's a tatty piece of paper with some black and white UN logos and crooked deaf symbols that they obviously made into a collage type thing and photocopied.
This scam is normally run by women and they are not afraid to use their children. If you are lucky they will just demand some money after you sign. If you are unlucky you'll get pickpocketd while distracted and signing. This happened to someone at my hostel. I was having none of it and told them in English I wasn't interested and tried to walk around. This pissed them off so they made a big scene about me being an "evil american who wants our deaf children to be murdered with bombs". Wailing and everything. It was quite something. I've come across alot of beggars and scammers but this was by far the most memorable.
My advice would be just pretend not to understand French or English, don't engage and keep your hands over your pockets. That pretty much goes for anyone that approaches you at any European tourist trap tbh