In the US, currently, if an individual donates more than $200 to certain types of political campaigns, that individual's name, address, occupation and employer must be included in campaign finance disclosures. $1000 > $200, so that's why the information is there.
As an aside: my previous job was in journalism, and generally in that field there's a (self-enforced) ethical code against making such donations largely because the employer's name is disclosed and could lead people to assume endorsement by a news outlet.
I don't know much about the law here, but isn't it required that you make such information public? That is, isn't that part of how campaign donations are tracked and regulated?
As an aside: my previous job was in journalism, and generally in that field there's a (self-enforced) ethical code against making such donations largely because the employer's name is disclosed and could lead people to assume endorsement by a news outlet.