In Paris, I've noticed a huge increase in visitors who are automatic targets for pickpockets. Partly due to the overall increase in tourists, and partly due to the fact that a lot of them are first-time visitors who think Paris is Disneyland and nothing bad will happen to them.
Here are some things I've noticed:
First, they often travel as a family or in a group.
Staying busy keeping track of your loved ones is easier than keeping track of your possessions. Thieves are counting on that.
Appoint someone to be in charge of directions ahead of time, and also appoint someone to keep track of bodies. Each person should be responsible for securing his/her own valuables. Never leave for the day with more money than you are prepared to lose, and leave passports, extra credit cards, photos, etc back in your hotel safe. Not everyone needs to bring all their gadgets along - the less you have to lose, the better.
Second, they tend to look like they have something worth stealing.
A real giveaway is a female wearing a cross-body bag and a frown, clutching the bag to her chest in a death grip - even when there is absolutely nobody around. This is not normal behavior, and will make you stand out like a target.
Men are worse, because they tend to "forget" where they are, rely on comfortable habits, and you can spot the wallets/gadgets in back pockets from a mile away. Vests or other special clothing also make you stand out like a target, and are really not necessary.
Backpacks are more interesting to thieves than you might think - even if you don't keep anything valuable in them. While you're busy fishing out a bottle of water, someone can easily help himself to your wallet or phone, which you're leaving unprotected.
If you look as if you have something valuable on your person, someone will be interested enough to check you out when the opportunity presents itself, and that someone might follow you for quite a while before you notice him/her.
Third, they don't look like they know what they're doing.
One person standing in the middle of the sidewalk trying to get his bearings won't attract much attention.
Two or more, especially with children involved, who stand in the middle of pedestrian traffic and are trying to look at a map, a gadget, or are busy arguing with each other will be easy targets. Quite often someone has a purse hanging wide open, too.
Everybody needs to figure things out, but you should move out of the way with your back to a wall, or go sit in a cafe while you get yourself oriented.
Fourth, they get "too comfortable".
Tired tourists will have a seat on a cafe terrasse, inside a nice restaurant, and forget that they aren't safe at home where there are no pickpockets. Professional pickpockets look just like anybody else, and will even tell you to have a nice day, after they have lifted your wallet. Kids who have been trained to grab and run are also very good at what they do. Never put your gadgets on a table if you aren't actually using them. Always keep your purse on your lap in front of you - looping the strap around the chair leg won't keep it safe. Always keep wallets inside front pockets, preferably with zippers or even a safety pin.
As far as the politics in Paris go, there are simply more illegal immigrant minor children than the city has resources to deal with. But this is not Paris' problem alone - it's everywhere in the Schengen Zone.