He had plenty of money and was willing to spend it, and so he was allowed to do pretty much as he pleased, provided he kept his purse open and did not steal from his neighbors.
But Blackbeard became tired of playing the part of a make-believe respectable citizen, and having spent the greater part of his money, he wanted to make some more.

Consequently he fitted out a small vessel, and declaring that he was going on a legitimate commercial cruise, he took out regular papers for a port in the West Indies and sailed away, as if he had been a mild-mannered New England mariner going to catch codfish.
The officials of the town of Bath, from which he sailed, came down to the ship and shook hands with him and hoped he would have good success.
After a moderate absence he returned to Bath, bringing with him a large French merchant vessel, with no people on board, but loaded with a valuable cargo of sugar and other goods.

This vessel he declared he had found deserted at sea, and he therefore claimed it as a legitimate prize.

Knowing the character of this bloody pirate, and knowing how very improbable it was that the captain and all the crew of a valuable merchant vessel, with nothing whatever the matter with her, would go out into their boats and row away, leaving their ship to become the property of any one who might happen along, it may seem surprising that the officials of Bath appeared to have no doubt of the truth of Blackbeard's story, and allowed him freely to land the cargo on the French ship and store it away as his own property.
But people who consort with pirates cannot be expected to have very lively consciences, and although there must have been persons in the town with intelligence enough to understand the story of pitiless murder told by that empty vessel, whose very decks and masts must have been regarded as silent witnesses that her captain and crew did not leave her of their own free will, no one in the town interfered with the thrifty Blackbeard or caused any public suspicion to fall upon the propriety of his actions..