ISTANBUL — Turkish authorities defied court orders and reaffirmed a ban on YouTube imposed after the posting of illicit recordings of top secret security talks that was cited by Prime Minister Tayyip Erdogan as part of a “dirty campaign” to topple him. Authorities imposed the ban on Google's video-sharing site on March 27 in the build-up to local elections, after weeks of leaked wiretaps which had emerged online, allegedly uncovering corruption in Erdogan's inner circle. Erdogan emerged from the polls with his popularity largely intact. Turkey's telecoms regulator said on Thursday it would not end a block on YouTube, despite court rulings lifting the ban. Access to Twitter had also been barred until the Constitutional Court ruled last week that this violated the law. – Reuters