Smugglers still exist and smuggling goods across the Pyrenees is still going on today. Differing tax levels lead to price differentials in different countries. When the countries are seperated by a common border 'leakage' of goods across the border from the low price to the high price country is possible and a strong financial incentive exists to smuggle.
Cigarettes in Spain are half the price of cigarettes in France. A 20kg sack of cigarettes smuggled into France from Spain can make you 1500 euros on the black market. Customs teams have people on the gound in the mountains attempting to stop the trafficking.