...and so back to the Tower several times, about the business of the pressed men [i.e. impressment, conscription], and late at it till twelve at night, shipping of them. But, Lord! how some poor women did cry; and in my life I never did see such natural expression of passion as I did here in some women’s bewailing themselves, and running to every parcel of men that were brought, one after another, to look for their husbands, and wept over every vessel that went off, thinking they might be there, and looking after the ship as far as ever they could by moone-light, that it grieved me to the heart to hear them. Besides, to see poor patient labouring men and housekeepers, leaving poor wives and families, taking up on a sudden by strangers, was very hard, and that without press-money, but forced against all law to be gone. It is a great tyranny.
There may be some contradictions or hypocrisy in Pepys' observation of this "tyranny", discussed in annotations here.
Nevertheless, impressment was a barbaric practice. No less barbaric is the modern practice of the draft, or stop-loss, or otherwise forcing human beings to be soldiers - including not allowing them to break their contracts.
Cross-reference: involuntary military service is a form of slavery.