I have heard fake brands you have bought can be seized and you are left with big fines... is this true?
In the case of counterfeit goods, customs officials are generally looking for imports with a large number of counterfeited items (which are then sold by "looky-looky" guys in the touristic spots throughout Europe, which in turn impacts sales of genuine items).
If you have a few of counterfeit goods in your luggage which they find, they may seize them but generally you won't be fined.
However, you may wish to look at the customs regulations on http://ec.europa.eu/taxation_customs/customs/index_en.htm and for those of the EU country you're entering. almost 8 years ago