No more unsafe than any major metropolitan area in the US .... and about as safe as any major metropolitan area in Europe.
That said, pickpockets/pursesnatchers in France are an issue -- especially on public tranposrt. However, French thieves win no prizes compared to the Italian thieves. Italian thieves exhibit true skill in their craft.
Only in Rome have I heard about a member of the Secret Service losing their principal firearm -- to a pickpocket -- while on duty.