This is basically the same story as the one already posted for innovage and 90ten so if you read those you'll have an idea of what the problem is. I don't have time to do a full recount but the basic jist is that BSI Boston is probably a legit company but they have some sketchy ways of recruiting.
You're told that they're looking to train managers. So you go in for a preliminary 15 min interview and then you get called back for an all-day second interview in which you're supposed to be shadowing someone. What they don't tell you is that you'll be shadowing someone in basically door-to-door sales in full business attire (which they insist you wear.) Everyone's very enthusiastic and very positive and the whole thing is insanely awkward because there is absolutely no advanced warning that you'll be wandering the city asking chinese restaurants if they'd like to be switched to verizon.
This might not be a scam in that it doesn't take your money but it is a huge waste of time for most people.