ACORN has been tied into bogus voter registration all over the country. ACORN pays their recruiters to sign up voters at one dollar per signature. Virtually all signing up are minoities. Incidents involving ACORN the past couple of weeks occurred in Minneapolis-St. Paul, Cincinnati, Columbus, OH and Philadelphia.
How does ACORN get their funding?
Cue the complaints of Republicans suppressing the black vote.
ACORN has also been active in Florida, where they "reregistered" people (that is, made a change to an existing registration, such as changing the party or address). In Tampa, they "reregistered" them as Republicans, in what I think was an attempt to cast suspicion on the GOP and confuse the issue even further. The fact that all the regs were filled out in the same hand and came from ACORN tipped off the election board folks...
ACORN/Project Vote is almost certainly breaking other election laws. For instance, in my jurisdiction, it is illegal to solicit signatures for petitions or sign people up for anything else when registering them to vote. It is also illegal to collect/use the information on registration forms to contact those people.