On July 8th, the Maricopa County Sheriff's department did a sweep on Mesa unannounced. Arpaio said they arrested 19 people in 5 hours and 18 of them were undocumented. The next day, they did a sweep in response to citizen (read racist) complaints in Cave Creek focusing in and around the Good Shepherd of the Hills Church, which was a location of a day labor center up until a few months ago. Also an article states, "Recently a federal court shot down an ordinance which would have loitering or soliciting work from a roadway illegal" (Source).
On July 15, the Phoenix PD brought over a dozen patrol cars to the area of Home Depot near the Macehualli day labor center. From an eyewitness account, a few people were detained in different locations, but the police did not stick around the area for long.
Arpaio is likely to hit Mesa soon again. It is highly likely that it will be unannounced.
There will be a protest against Arpaio at his booksigning at borders books at 2402 E Camelback Road, phoenix tomorrow/saturday at 12:30pm.