Getting suspended from adwords for using multiple accounts

I have been using my Google Adwords vouchers to advertise and since your only allowed one per account, I just created a new account everytime. I have been getting away with this for probably the last couple years until a week ago when I had 2 of my accounts suspended for doing this. I am wondering if Google just added a new detection system and if anyone has had this happen to them in the last week as well? Also, if anyone has any pointers to help prevent this from happening in the future?

this happens all the time not just from a week ago.

I'm getting banned from past 6 months! LoL

Adwords banned 15 accounts of mine within the last 2 months thats not new try different ip per account maybe

Too bad. That's now 4 of my accounts that have been suspended. I guess I will just have to money out of my own pocket now.

Do not make multiple accounts at once. Keep gap of 2-3 days.