Morgan Stanley cut its price target on Facebook shares to $200 from $230 on Wednesday, citing concerns about the social media company's ad sales because of its data scandal.

"Following FB's recent data/privacy issues and its announcement that it will end partnerships with third party data providers, we sense growing investor concern about near-term ad revenue," analyst Brian Nowak wrote in a note.

"While we think FB's high advertising performance speaks to the value users get out of the ads served, general consumer dislike towards advertising and increased data scrutiny could cause more users to opt-out of sharing data with FB," he said.

Nowak also said he expects Facebook's capital spending to increase by 2 percent as the company invests more in data safety. He also sees advertising revenue growing at a slower rate in 2018 and 2019. Facebook shares declined 0.7 percent on Wednesday to $155.10. Morgan Stanley's new price target implies a 29 percent upside from Facebook's closing price on Wednesday.

Facebook was one of the best-performing stocks during the past year before the scandal broke last month that political research firm Cambridge Analytica had gathered data from 50 million Facebook profiles without permission.

That resulted in a stock decline of more than 10 percent as investors grew concerned that Facebook's handling of personal data could lead to government regulation and a decrease in daily active users, a key metric for the company.

Still, the Morgan Stanley analyst remains bullish on the stock long term. "We have spoken with 8 agencies/advertisers now and don't sense any material reduction in ad spend," he said. "In fact, over the long-term, we think the elimination of third parties is smart strategically as it will highlight FB's leading reach and first party data advantage."