Barclays do have a lot anti fraud measures in place. very annoying. I used to always get the automated calls to check the last few transactions are mine.
Its flagged up my broadband payments all of a sudden when I've been paying it by direct debit for the last 3-4 years, its stopped my paying for a Dominos pizza when I've ordered online and paid with the same card
HSBC are generally more known to be a lot less hassle, if this has any bearing if they suffer from more fraudulent account transactions I dont know.
I remember from my Uni days HSBC seemed to be the easiest to get an increased overdraft limit. A case of sign here. Barclays, my friend had to tell someone over the phone his normal weekly spend/income to get it increased.