Why: I'm not sure whether or not I should pretend to be offended. Is it related to Shylock?
Answer: No! First, the definition:
n. a person who uses unscrupulous, fraudulent, or deceptive methods in business. Historically, it has mainly been applied to lawyers.The term first appeared in print in the New York newspaper The Subterranean in 1843 in a story about the notorious prison known as The Tombs. In the 1840s, it was full of unscrupulous and parasitic charlatans who pretended to be lawyers and officers of the court, also known as "pettifoggers." The editor of that newspaper described shysters like a-this:
Ignorant blackguards, illiterate blockheads, besotted drunkards, drivelling simpletons, ci-devant mountebanks, vagabonds, swindlers and thieves make up, with but few exceptions, the disgraceful gang of pettifoggers who swarm about its halls.In that decade, the word went from meaning "an incompetent person" to specifically mean "a crooked lawyer."
It comes from the German word Scheisser, "an incompetent person," which came to New York through German immigrants. That word comes from Scheisse, "shit," as in an incontinent old man. British slang of the same period used the same word, spelled shicer, that meant "a worthless person."
So anyway, yes, offended, but not for the reason I thought.
Source: World Wide Words
The More You Know: The Tombs is the nickname for the Manhattan Detention Complex at 125 White St. Maybe you have heard about it on "SVU." The old and new buildings looked like this and this (in 1896 and 1907):
Now they are connected by a Bridge of Sighs, the view from which is the last thing convicts see before their imprisonment (how adorbs is that name?). It's named after the one in Venice (the Ponte dei Sospiri), and there are a bunch more in other places.