Xenophobia is likely at an all-time high in the United Kingdom, and this unfortunate incident is a good example. This is the ugly side of nationalism. However, it is important to keep in mind that this is just one incident. The 52% of people who voted for Leave are not all xenophobic.
With Poles being abused in the United Kingdom, reports suggest it is a sign of xenophobia. There are 800,000 Polish people in the UK, one of the largest migrant communities. Most of the attacks were targeted, hence it suggests a clear case of xenophobia. The Polish ambassador has also voiced out his concerns for the Polish community in UK.
Any form of prejudice against a certain group of nationalities is a form of racial abuse which is inexcusable - this is unwarranted xenophobia. There can be no excuse for this sort of bigoted behaviour and it should not be tolerated in any country or societal group. This should be stamped out where found.
The controversial "Brexit" vote raised concerns that the United Kingdom is isolating itself even further by closing its borders to immigrants and cultural exchange with the European Union. One disturbing example of this is the horrific treatment of Polish people that has been reported. Xenophobia is the fear of outsiders, and mistreatment of immigrants is certainly a symptom of this.