Can I get deported while I'm waiting for the government to review my U visa petition?
If you get put on the U visa waitlist or get a bona fide determination, it is unlikely, but not impossible, that Immigration and Customs Enforcement (ICE) will try to deport you. Once you are on the waitlist or get a bona fide determination, you get “deferred action.”1 This is not a real immigration status, but it allows USCIS to give you a work permit.
However, while you are waiting to hear if you get on the waitlist or if USCIS has made a bona fide determination, you will not have any sort of legal status or deferred action, so you could be at risk of deportation.
If you are in immigration court currently because the government is trying to deport you, see Can I apply for U visa status if I am in immigration court for deportation (“removal”) proceedings? for more information.
1 8 CFR § 214.14(d)(2); USCIS Policy Manual, Vol. 3, Part C, Ch. 5