There is a prohibition against eating chameitz that was owned (and not sold) by a Jew over Pesach. This poses a potential issue in purchasing from a number of stores in Baltimore immediately after Pesach as one of the major the distributors in the area is Jewish and does not sell his chameitz. Please see the attached link for stores where chameitz may and may not be purchased: http://www.star-k.org/articles/wp-content/uploads/2017/03/StoresAfterPesach_2017.pdf
Please bear in mind that one may buy non-chameitz items from those stores.
For those who drink beer, this issue affects a number of brands. Please see the list of forbidden beers: http://www.star-k.org/articles/wp-content/uploads/2017/04/BeerAlertListing.pdf