Italy has begun expelling Romanians it regards as a threat to public safety.
Under European Union law, an EU state can only deport citizens of another European state under strict conditions.
Romanian President Traian Basescu has asked his government to complain to the European Commission - but Commission spokesmen say Italy may well be within its rights.
Do Romanians have a right to enter other EU states?
Yes. Romania has been a member of the European Union since 1 January, so Romanians have a right of free movement across the 27-member bloc. They only need a valid passport.
Do they have a right to live in other EU states?
Yes, but there are two exceptions.
Firstly, the host country can deport them to their country of origin after 90 days if they do not have a job, sickness insurance or the means to support themselves (and if they have no family member in the host country capable of supporting them). This is to prevent people becoming a burden on the host country's social safety net.
Secondly, they can be deported if they present a threat to public order, public security or public health.
They must, however, have an opportunity to appeal, and must be given a month to leave, except in emergencies.
Do they have a right to work in other EU states?
EU states are allowed to restrict access to their labour markets for a transitional period, after a new country joins the bloc.
So citizens of Romania - and of Bulgaria, which joined at the same time - do not have an automatic right to work in other EU states.
Only 10 member states have given Romanians and Bulgarians full access to their labour markets. These are Finland, Sweden, Cyprus, the Czech Republic, Estonia, Latvia, Lithuania, Poland, Slovakia and Slovenia.
Some member states still have restrictions in place on workers from countries that joined the EU in 2004.
Can groups be expelled?
No. There is no guilt by association. If someone is deported, he or she must be deported because of his or her own actions, or financial circumstances.
Does it make any difference how long a person being deported has lived in a country?
If they have lived in a country for more than 10 years they can only be deported in exceptional circumstances.
Can EU citizens be stopped on the border of another EU country and denied entry?
Yes, under certain conditions, for example, if they are wanted by police.
But this would only occur if they were entering or leaving a country that was not a member of the Schengen "no borders" pact.
Romania is not yet a member.